[Koha] [translate] Migrate Pootle to Weblate

[Jonathan Druart]

Hello everybody,

If you are a translator of Koha you should read this.

Pootle is dead and we should move to Weblate, which is an active and
well maintained project.
We have been setting up a test server to let translators see how it goes.
THIS IS A TEST SERVER: none of the changes will be saved!

There are some changes in how the projects are structured.
We will now have 2 projects: "koha" and "koha-manual". Each will
contain several "components".
One component in Pootle can only track on po file, which means we need
one component per po file:
https://translate.test.koha-community.org/projects/koha/ shows
https://snipboard.io/rtKdTS.jpg

It can be a bit disturbing at first, but there is this view:
https://translate.test.koha-community.org/languages/es/koha/ that
shows the progress per language: https://snipboard.io/UCJ1Ky.jpg

The big win are:
* We should no longer get "Critical errors: Python brace placeholders"
(to be confirmed)
* Translation changes will be propagated between the components of a
given project, and so between versions: if you modify a string for
23.05 it will also modify it for the other branches! (to be confirmed
as well!)

guest user (not logged in) can only make suggestions:
https://translate.test.koha-community.org/

User reviewer/6Mx1&a2S$HU*1KNbzCZV can accept suggestions.

You are welcome to test and provide feedback!

There is still a lot of work before effectively doing the migration,
but we need first to know if users/translators are happy with it!

Let us know!
Cheers,
Jonathan

PS: About the structure of the projects, I've contacted the author of
Weblate: https://github.com/WeblateOrg/weblate/discussions/9556
Next version will add a mecanism to structure components within a project!