imgPath onCreateFileImageThumbnailSource would throw FileNotFoundException

If the sysadmin decides that StoreRemoteMedia plugin should store
original, then its thumbs will be regenerated as well, making it safe to
delete them if needed. Beware that Embed plugin never stores the original tho.

Fix some buggy ones, especially Embed crop

This bug was introduced with the commit "[Media] Fix issues with database file storage"
due to the API change "File::getByHash now returns a yield of files".

I had updated this function on that commit but had missed this little detail.

[StoreRemoteMedia] Upgrade plugin to use the new Media system

API Changes:
- Added getters to File to better formalize the ideas of the commit "[Media] Fix issues with database file storage"

UI Changes:
- Now presented thumbnails are actual thumbnails (bug fix)
- Attachment actions have a slightly more extended behaviour

Many other minor bug fixes...

Fixed file quota as well.

There can be more than one file for the same filehash IF the url are different.

Possible states:
  - A file with no url and with filename is a local file.
  - A file with an url but no filename is a remote file that wasn't fetched,
    not even the thumbnail.
  - A file with an url and filename is a fetched remote file (maybe just a
    thumbnail of it).
  - A file with no filename nor url is a redirect.

Routes:
  Given these states, updated routes so that an attachment can only be
  retrieved by id and a file by filehash.

Major API changes:
  File::getByHash now returns a yield of files

Major UI changes:
  - Now remote non stored files are presented.
  - /view became preferred
  - Redirects to remote originals are preferred.

Many other minor bug fixes...

Removed by mistake with 9cc7df51d6#L50

Fix OAuth and Realtime issues introduced in 9a515b9234

[DATABASE] Fix an empty default value mistake introduced in
fde929b151

[DATABASE][PostgreSQL] Avoid use of pg_constraint.consrc, which was removed in
PostgreSQL 12.

[DATABASE][MariaDB] Fix a typo introduced in aed2344bd4

[DAEMON] Wrap an assignment inside "switch":
a follow-up to adc689cb15

This also fetches a necessary update from the XMPPHP upstream.

Using a left outer join as a semi-join is not a valid approach.
Can still be used for an anti-semi-join.

Ideally the character set should be set with the connection, and so this is
exactly what's being done now.

And now the character set code is attempted to be generalised.

Changing `character_set_server` requires root permissions and rebooting
the server.

Which is impossible on shared web hosting services.

So use `character_set_database`. This variable can be changed with
user permissions using `ALTER DATABASE`.

Try to also employ an id when possible.
Involves reworking some of the indices.

"Magic quotes" were removed in PHP 5.4, no need to mitigate it anymore.

Avoid implode() with the join()-like order of arguments which was deprecated
since PHP 7.4 and implicitly since PHP 5.3.
Also avoid implode() with an implicit separator for stylistic reasons.

mktime() with no arguments has been deprecated since PHP 5.1.

And remove common_validate_utf8() which is now unused.

It does not throw but return null.

TemporaryFile::commit throws instead of returning a bool.

This resulted in N=0 and empty "modified" in cache.

Either use them in a subroutine call or put parentheses around the assignment.

And adopt it all over the code.

The previous approach sent the key values twice, which for large sets is
twice as bad.

As an optional feature of this approach multiGet now allows retrieving tuples
in exact order and amount of the requested key values.