Docs: Replace Current theme with Active theme in various DocBlocks

[audrasjb]

After [52580], it would be nice to also update various Docblocks to replace "Current Theme" with "Active Theme".

Follow-up to [52580].
See #54770.

Trac ticket: https://core.trac.wordpress.org/ticket/54831

[Presskopp]

I give to consider that we also have lots of references to "current theme" like on

​https://developer.wordpress.org/reference/functions/get_template_directory/

and we have functions in core: current_theme(), current_theme_supports(), validate_current_theme()

and some usages of

$current_theme_data and 'current_theme_has_errors'

Do they all need to be renamed?

[audrasjb]

Good point @Presskopp. For me, this ticket only aims to take care of the Docblocks occurrences, as their content is publicly displayed on HelpHub.

Once this is eventually merged into core, we can open another ticket to address variable naming.

And ultimately, maybe deprecate some functions and hooks, but that's the most difficult part as it introduces breaking changes :)

[audrasjb]

Thanks for the review @costdev 🙂
I think we're good to go 👍

[audrasjb]

In 52610:

Docs: Replace "Current theme" with "Active theme" in various DocBlocks.

This change replaces "Current theme" with "Active theme" in various DocBlocks for better consistency with user-facing strings.

Follow-up to [52580].

Props Presskopp, audrasjb, costdev.
Fixes #54831.
See #54770.

Committed in https://core.trac.wordpress.org/changeset/52610