Use lxqt-transupdate to update translations in cmake

[agaida]

Removed not needed code
Removed Qt4 support
supersedes /pull/36

[palinek]

IMO we should change the logic of getting sources and ts files in lxqt-transupdate and use here the ${TR_SOURCES} and ${tsFiles} .... so the configuration is exactly on one place (not in CMakeLists.txt together with .translation-update)

[agaida]

@palinek - i'm not convinced - it would make sense the other way round. To be verbose of: I don't see any sense in any cmake magic here - you might see it different. But .translation-update is exactly the scheme that is used in weblate too. So please see .translation-update as a kind of documentation. Might sound crazy, but isn't - let's use .translation-update as a single point of failure. We will notice it if something goes wrong here very fast. The point is: If we change some translation directories (moving or renaming paths) this will break weblate too. So i would like it to fail in cmake too. That would be great.

[luis-pereira]

@agaida Is this PR still valid ?

[stefonarch]

I think this is not a good idea anymore, it would need always committing all pending translations in weblate first.

Now always before running lxqt-transupdate it is mandatory to

• commit and push all pending translations in weblate
• lock the component to prevent changes

Run it, commit and merge it and only after that unlock weblate component. Otherwise there will be rebase issues in weblate,

[redtide]

So please see .translation-update as a kind of documentation

FWIW I hope to see .translation-update and translations/CMakeLists.txt to go away and use only CMake automation or lxqt-transupdate as manual command. Those files are just confusing and seem also unneeded. I lost hours to try to understand how those files works, and still IDK what those are for.