Backport: Update default templates info

[ntsekouras]

We need to backport the recent changes from Gutenberg PRs: ​https://github.com/WordPress/gutenberg/pull/51428 and ​https://github.com/WordPress/gutenberg/pull/52048

Trac ticket: https://core.trac.wordpress.org/ticket/58713

This PR back ports the changes from this Gutenberg PR: ​https://github.com/WordPress/gutenberg/pull/51428

[isabel_brison]

In 56145:

Editor: update template titles in browse mode.

Adds more meaningful titles to templates in the browse mode template list.

Props ntsekouras, audrasjb.
Fixes #58713.

Committed in r56145 / ​9d141e5.

[kebbet]

The description for Author archives was updated in [56145] to :
Displays a single author\'s post archive. This template will serve as a fallback when a more a specific template (e.g., Author: Admin) cannot be found.

That seems to be incorrect, and should be something like this:
Displays a single author\'s post archive. This template will serve as a fallback when a more specific template (e.g., Author: Admin) cannot be found.

[audrasjb]

Fixed by [56182] (forgot to fix the ticket directly in the commit).

[SergeyBiryukov]

Thanks for the commits!

It appears that there is now a minor inconsistency in the descriptions:

• Single Entries: Displays any single entry, such as a post or a page. This template will serve as a fallback when a more specific template (e.g., Single Post, Page, or Attachment) cannot be found.
• Author Archives: This template will serve as a fallback when a more specific template (e.g., Author: Admin) cannot be found.
• Category Archives: Displays a post category archive. This template will serve as a fallback when more specific template (e.g., Category: Recipes) cannot be found.
• Tag Archives: Displays a post tag archive. This template will serve as a fallback when more specific template (e.g., Tag: Pizza) cannot be found.

Note the lack of the "a" article in the latter two strings. It should probably be reinstated, see 58713.diff​.

[isabel_brison]

In 56230:

Editor: fix typos in templates info.

Fixes two small typos in wp-includes/block-template-utils.php.

Props SergeyBiryukov.
Fixes #58713.