All the list item separators within text must be translatable

[afercia]

Description

Splitting this out from #58201 (comment)

While searching for join( ', ' through the codebase, it turned out that such a separator is used to delimit list items embedded in translatable strings. That approach may work for English and other Western languages but it's not okay. The list item separator needs to be translatable.

In WordPress core, the wp_get_list_item_separator() function internally applies a translation function and returns a separator string. See also WP_Locale->get_list_item_separator().

Gutenberg needs a similar approach where the list item separator and possibly in the future other separators, etc. are in a centralized location and can be reused throughout the codebase.

So far, in #58256 there is a proposal to add a l10n object to packages/editor/utils to provide a translation mechanism for the list item separator.

Whatever the final implementation will be, all the occurrences of a comma used as list item separator within the user interface text needs to be replaced with a translatable string.

Step-by-step reproduction instructions

N/A
Look for usage of such .join( ', ' ) pattern in the codebease e.g.:

gutenberg/packages/editor/src/components/entities-saved-states/entity-type-list.js

Line 62 in 5795b6e

<PanelRow>{ globalStylesChanges.join( ', ' ) }</PanelRow>

This example is used here in the Global Styles, when saving changes:

Screenshots, screen recording, code snippet

No response

Environment info

No response

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[afercia]

Update: #58256 tried to introduce a l10n utility object containing the translatable list item separator. It was hten decided to simplify the affected translatable string. The general issue is still valid though as there are other occurrences of non-translatable commas an the editor doesn't have a way to handles these cases.