CMS6: Default to utf8mb4

[maxime-rainville]

Description

A while back, we put some effort in making easy to set up up your database to store Emojis and fanciful characters in your DB fields. However, we didn't want to force people to upgrade their project to the 4-bit UTF8 charset ... because breaking change.

We did add a better config in recipe-cms so people creating brand new projects would get the 4-bit charset.

However, we forgot to update the default charset and collation in CMS 5 ... so people still have to keep that snippet in their YML config if they want to use 4-bit UTF8 char.

We should update CMS 6 to use 4-bit UTF8 char out of the box.

Additional context or points of discussion

This bit should be removed in CMS 6: https://github.com/silverstripe/recipe-core/blob/5/app/_config/mysite.yml#L7-L16

Instead the matching config values should be set directly in MySQLDatabase:
https://github.com/silverstripe/silverstripe-framework/blob/5/src/ORM/Connect/MySQLDatabase.php#L28-L76

Validations

• You intend to implement the feature yourself
• You have read the contributing guide
• You strongly believe this feature should be in core, rather than being its own community module
• You have checked for existing issues or pull requests related to this feature (and didn't find any)

Pull request

• ENH Default DB settings to use 4 bytes to store UTF8 characters #11431
• ENH Remove old logic to default UTF8 DB setting to 4 bytes recipe-core#102
• DOC Add entry about utf8mb4 encoding update to changelog developer-docs#602

[GuySartorelli]

Makes sense to me

[GuySartorelli]

@maxime-rainville Are you still interested in doing this?

[maxime-rainville]

Sorry ... got busy with life, StripeCon presentation and screaming at AWS over the last two months. Just got a bunch of PR for this one.

[GuySartorelli]

PRs merged. Thanks for taking care of that