Merge two similar translation strings when using get_space_allowed()

[ramiy]

Both multisite_over_quota_message() and upload_is_user_over_quota() output similar error messages when the passing the allowed storage quota. The first is for multisite and the second is for the media library, but both functions use get_space_allowed().

1. Sorry, you have used all of your storage quota of %s MB.

2. Sorry, you have used your space allocation. Please delete some files to upload more files.

Those two messages can be merged into one:

• Sorry, you have used your space allocation of %s MB. Please delete some files to upload more files.

[ramiy]

Add translators comments

[ramiy]

We can also merge the string used in the deprecated wpmu_checkAvailableSpace() function.

[SergeyBiryukov]

A similar string is also used in wp_xmlrpc_server::mw_newMediaObject().

[Jonathandejong]

Apologies, added a bit too much.. new patch coming right up.

[Jonathandejong]

fixes -3.patch

[pento]

Instead of %s MB, this would probably be better if we took the return value of get_space_used(), multiply it by MB_IN_BYTES, and feed that number to size_format(). Given that sites have fairly large size limits these days, limiting it to MB is going to make for some large numbers.

[ramiy]

@pento

For now we can use %s placeholder in the translation string.

Later, if we will decide to change the value, it won't affect the translation string.

[SergeyBiryukov]

In 45082:

I18N: Merge similar strings about allowed space allocation in Multisite.

Props ramiy, Jonathandejong, pento.
Fixes #42223.

[SergeyBiryukov]

In 45084:

PHPCS: Fix WPCS violation in [45082].

See #42223.