Allow more app icons to be shown in the top app bar

[e-alfred]

Steps to reproduce

1. Install more than 10-15 apps
2. Access Nextcloud in a browser on a widescreen monitor

Expected behaviour

More app icons should be shown (instead of 7) depending on the width of the screen.

Actual behaviour

Only 7 app icons are shown and a lot of space to the right at the top bar is wasted on big widescreen monitors.

Server configuration

Operating system: Linux server 4.4.0-78-generic #99-Ubuntu SMP Thu Apr 27 15:29:09 UTC 2017 x86_64

Web server: Apache/2.4.18 (Ubuntu) (apache2handler)

Database: mysql 5.7.18

PHP version: 7.0.18-0ubuntu0.16.04.1
Modules loaded: Core, date, libxml, openssl, pcre, zlib, filter, hash, Reflection, SPL, session, standard, apache2handler, mysqlnd, PDO, xml, bcmath, bz2, calendar, ctype, curl, dom, enchant, mbstring, fileinfo, ftp, gd, gettext, gmp, iconv, igbinary, imagick, imap, interbase, intl, json, ldap, exif, mcrypt, mysqli, odbc, pdo_dblib, PDO_Firebird, pdo_mysql, PDO_ODBC, pdo_pgsql, pdo_sqlite, pgsql, Phar, posix, pspell, readline, recode, redis, shmop, SimpleXML, smbclient, soap, sockets, sqlite3, sysvmsg, sysvsem, sysvshm, tidy, tokenizer, wddx, xmlreader, xmlrpc, xmlwriter, xsl, zip, libsmbclient, Zend OPcache

Nextcloud version: 12.0.0 - 12.0.0.29

Updated from an older Nextcloud/ownCloud or fresh install: Upgrade from NC 11

Where did you install Nextcloud from: tar.gz from Nextcloud page

Signing status:

Signing status

[]

List of activated apps:

App list

``` Enabled: - activity: 2.5.2 - admin_audit: 1.2.0 - bookmarks: 0.10.0 - bruteforcesettings: 1.0.2 - calendar: 1.5.3 - checksum: 0.3.4 - circles: 0.10.0 - comments: 1.2.0 - contacts: 1.5.3 - dav: 1.3.0 - deck: 0.1.4 - drawio: 0.8.8 - external: 2.0.3 - federatedfilesharing: 1.2.0 - federation: 1.2.0 - files: 1.7.2 - files_accesscontrol: 1.2.4 - files_automatedtagging: 1.2.2 - files_downloadactivity: 1.1.1 - files_external: 1.3.0 - files_pdfviewer: 1.1.1 - files_reader: 1.0.4 - files_retention: 1.1.2 - files_sharing: 1.4.0 - files_texteditor: 2.4.1 - files_trashbin: 1.2.0 - files_versions: 1.5.0 - files_videoplayer: 1.1.0 - firstrunwizard: 2.1 - flowupload: 0.4 - gallery: 17.0.0 - gpxedit: 0.0.6 - issuetemplate: 0.2.1 - logreader: 2.0.0 - lookup_server_connector: 1.0.0 - mozilla_sync: 1 - music: 0.3.13 - news: 11.0.5 - nextcloud_announcements: 1.1 - notifications: 2.0.0 - oauth2: 1.0.5 - ocdownloader: 1.5 - onlyoffice: 1.0.4 - ownbackup: 17.5.0 - ownnote: 1.08 - passman: 2.1.2 - password_policy: 1.2.2 - provisioning_api: 1.2.0 - rainloop: 5.0.0 - richdocuments: 1.12.31 - serverinfo: 1.2.0 - sharebymail: 1.2.0 - socialsharing_email: 1.0.1 - spreed: 2.0.1 - survey_client: 1.0.0 - systemtags: 1.2.0 - tasks: 0.9.5 - theming: 1.3.0 - twofactor_backupcodes: 1.1.1 - twofactor_totp: 1.3.0 - updatenotification: 1.2.0 - weather: 1.4.2 - workflowengine: 1.2.0

Disabled:

• encryption
• user_external
• user_ldap

</details>

**The content of config/config.php:**
<details>
	<summary>Config report</summary>

{
"instanceid": "REMOVED SENSITIVE VALUE",
"passwordsalt": "REMOVED SENSITIVE VALUE",
"trusted_domains": [
"REMOVED SENSITIVE VALUE"
],
"datadirectory": "/var/www/owncloud/data",
"dbtype": "mysql",
"version": "12.0.0.29",
"installed": true,
"mail_from_address": "REMOVED SENSITIVE VALUE",
"mail_smtpmode": "smtp",
"mail_domain": "REMOVED SENSITIVE VALUE",
"forcessl": true,
"mail_smtpauthtype": "PLAIN",
"mail_smtpauth": true,
"mail_smtppassword": "REMOVED SENSITIVE VALUE",
"mail_smtphost": "REMOVED SENSITIVE VALUE",
"mail_smtpport": "REMOVED SENSITIVE VALUE",
"mail_smtpname": "REMOVED SENSITIVE VALUE",
"mail_smtpsecure": "tls",
"filesystem_check_changes": 1,
"theme": "",
"maintenance": false,
"secret": "REMOVED SENSITIVE VALUE",
"overwrite.cli.url": "REMOVED SENSITIVE VALUE",
"forceSSLforSubdomains": true,
"loglevel": 0,
"logtimezone": "REMOVED SENSITIVE VALUE",
"custom_csp_policy": "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; frame-src *; img-src *; font-src 'self' data:; media-src *",
"dbname": "REMOVED SENSITIVE VALUE",
"dbhost": "localhost",
"dbuser": "REMOVED SENSITIVE VALUE",
"dbpassword": "REMOVED SENSITIVE VALUE",
"memcache.local": "\OC\Memcache\Redis",
"redis": {
"host": "localhost",
"port": 6379
},
"memcache.locking": "\OC\Memcache\Redis",
"trashbin_retention_obligation": "auto",
"updatechecker": false,
"log_rotate_size": 104857600,
"htaccess.RewriteBase": "/owncloud",
"mysql.utf8mb4": true
}

</details>

**Are you using external storage, if yes which one:** Array
(
    [0] => \OC\Files\Storage\Local
    [1] => \OCA\Files_External\Lib\Storage\FTP
    [2] => \OC\Files\Storage\DAV
    [3] => \OCA\Files_External\Lib\Storage\OwnCloud
    [4] => \OCA\Files_External\Lib\Storage\SFTP
    [5] => \OCA\Files_External\Lib\Storage\AmazonS3
    [6] => \OCA\Files_External\Lib\Storage\Dropbox
    [7] => \OCA\Files_External\Lib\Storage\Google
    [8] => \OCA\Files_External\Lib\Storage\Swift
    [9] => \OCA\Files_External\Lib\Storage\SFTP
    [10] => \OCA\Files_External\Lib\Storage\SMB
    [11] => \OCA\Files_External\Lib\Storage\SMB
)


**Are you using encryption:** no

**Are you using an external user-backend, if yes which one:** LDAP/ActiveDirectory/Webdav/...

### Client configuration
**Browser:** Firefox and Chrome

**Operating system:**

### Logs
#### Web server error log
<details>
	<summary>Web server error log</summary>
	```
	Insert your webserver log here
	```
</details>

#### Nextcloud log (data/nextcloud.log)
<details>
	<summary>Nextcloud log</summary>
	```
	Insert your Nextcloud log here
	```
</details>

#### Browser log
<details>
	<summary>Browser log</summary>
	```
	Insert your browser log here, this could for example include:

	a) The javascript console log
	b) The network log
	c) ...
	```
</details>

[ghost]

Duplicate of #5121 #5135