Make three untranslatable strings, translatable

[jrf]

While working on #31950, I came across three untranslatable strings.

Sending a separate patch in for those now at johnbillion's suggestion.

I *have* included the string in wp_db.php as well in this patch, in contrast to his suggestion, as wp_load_translations_early() is called within the same function and __() is used for other strings within the function too, so language functions should be available.

[SergeyBiryukov]

There's one more string several lines above: tags/4.1.1/src/wp-includes/wp-db.php?marks=1239#L1224​.

[jrf]

@SergeyBiryukov you're completely right - uploaded a new patch which includes that string too.
Sorry, the other patch from which I subtracted this one focused only on echo statements, so I missed this one ;-)

[SergeyBiryukov]

No apologies necessary, thanks for the patch :)

[ocean90]

In 33006:

wpdb: Make "WordPress database error:" translatable.

props jrf.
see #32021.

[ocean90]

In 33007:

Make WP_Locale::rtl_src_admin_notice() translatable.

props jrf.
see #32021.

[ocean90]

In 33008:

Remove unnecessary feedback message from WP_Importer::is_user_over_quota().

fixes #32021.

[ocean90]

Replying to ocean90:
None of the importer plugins are using this method currently. I'm also not quite sure in which context WP_Importer can be run so adding i18n as a dependency could break things.

[markoheijnen]

Shouldn't we skip translating the error messages in error_log? If people want to collect error logs then making the message variable makes that almost impossible.