[4.0][com_media] RTL: adapting media manager to rtl + some

[infograf768]

Summary of Changes

This PR corrects the rtl display of the media manager.
Plus:
It also modifies 2 language strings (dates) and allows Jalali date to be displayed.
It adds a missing lang string.
It adds to the frontend com_media.ini the missing lang strings to let create site only lang packs.
It orders language strings in the ini files as well as in default_texts.php

What it does not do:
It does not delete the frontend language strings which are no more used.
It does not solve the frontend infobar absent display.
It does not solve frontend Inserting image in article TypeError: Joomla.getImage is not a function

Testing Instructions

Install the Persian Language pack (administrator/index.php?option=com_installer&view=languages)
Switch to Persian in administrator.
Display the media manager.

Patch and run npm ci

Before patch

This is what we get for LTR

This is what we get for RTL

After patch

This is what we should get for RTL

Supplementary test

After patch and npm ci
Enable Debug lang.
Delete or change name of administrator/language/en-GB/en-GB.com_media.ini in order to load ONLY the front end file.
Edit an article in front end and display the xtd Images modal
There should not be any more untranslated strings

Documentation Changes Required

None

[C-Lodder]

Do you need the fullstop (.) at the end?

[infograf768]

I have not corrected various existing lang strings.
We do have already
COM_MEDIA_DELETE_SUCCESS="Item deleted." for example.
or
COM_MEDIA_ERROR="An error occurred."
I think such messages should end with a period.

As you can see the capitals and periods for these are not consequent.
I can though modify them on the model of
COM_CATEGORIES_SAVE_SUCCESS="Category saved." etc.

In this case, we should have I guess

COM_MEDIA_UPLOAD_COMPLETE="Upload complete."
COM_MEDIA_UPLOAD_FILE="Upload file"
COM_MEDIA_UPLOAD_SUCCESS="Item uploaded."

I guess these can be modified later on by specialists in a specific PR, to not interfere with this PR.
What do you think?

[infograf768]

Looks also that
COM_MEDIA_UPLOAD_FILE is not used at all in 4.0

These ini will have to be drastically cleaned up when media manager gets more stable.

[wilsonge]

Thanks!