Issue/7996 actionable empty states (Part 1)

[theck13]

Fix

Add the actionable empty state view class, ActionableEmptyView, and implement a single instance of the actionable empty states described in #7996. Only one instance is included in this pull request to show the new class in action and keep the changeset small. The remaining actionable empty states in #7996 will be included in a subsequent pull request. See the screenshots below for illustration.

Test

1. Go to My Site tab.
2. Tap Media item under Publish section.
3. Tap All, Images, Documents, Videos, and Audio tabs.
4. Notice empty view when no media is present.
5. Tap Upload Media button.
6. Notice new media popup menu.

[0nko]

Looks great 👍

[SylvesterWilmott]

Looking good!

Does the text area have a maximum width? Also what does it look like with a long text string there (3 lines)?

[theck13]

Does the text area have a maximum width?

The title and subtitle (not shown in the screenshots above) have a maximum width of 300dp and a horizontal margin of 30dp.

Also what does it look like with a long text string there (3 lines)?

Here's what the title looks like with a long text string of three lines.

[theck13]

After chatting with @SylvesterWilmott, we decided to remove the maximum height of the image and update the maximum width of the text to 440dp. See the screenshots below for illustration.

[SylvesterWilmott]

Looks great @theck13 !

[0nko]