Bump bundled theme versions for 5.4

[desrosj]

Previously:

• #48944 (5.3.1)
• #47172 (5.2)
• #46070 (5.1)
• #45792 (5.0.3)

Looking at the changed files since 5.3.2, each bundled theme has changes and should receive a new version.

@ianbelanger is preparing a patch now.

[ianbelanger]

Version bump

[SergeyBiryukov]

For reference, Twenty Nineteen has some CSS changes from [47327] and [47339] after running the build task. These should be safe to backport to the branch.

[SergeyBiryukov]

In 47538:

Twenty Nineteen: Update style-editor.css and style-rtl.css after running the build task.

Follow-up to [47327], [47339].

Props ianbelanger.
Reviewed by desrosj, SergeyBiryukov.
Merges [47536] and [47537] to the 5.4 branch.
See #48526, #49410, #49743.

[desrosj]

In 47539:

Bundled Themes: Bump version numbers and update changelogs in default themes for WordPress 5.4.

Props ianbelanger, desrosj, SergeyBiryukov.
Fixes #49743.

[desrosj]

Reopening to backport.

[desrosj]

In 47540:

Bundled Themes: Bump version numbers and update changelogs in default themes for WordPress 5.4.

Reviewed by desrosj, SergeyBiryukov.
Props ianbelanger, desrosj, SergeyBiryukov.
Merges [47539] to the 5.4 branch.
Fixes #49743.

[superpoincare]

The main stylesheet style.css now has dates as the version.

For example:

​https://github.com/WordPress/WordPress/blob/master/wp-content/themes/twentyseventeen/functions.php#L451

<?php
wp_enqueue_style( 'twentyseventeen-style', get_stylesheet_uri(), array(), '20190507' );

So the bump should also change the lines in functions.php

It doesn't affect all themes as some bundled themes like Twenty Nineteen and Twenty Twenty use the version in the stylesheet but for others it does.