CMake: Add LGPL Option

[HTRamsey]

Closes #8252

[DonLakeFlyer]

If this removes the usage of Charts then the PX4 tuning page also uses charts. Can't remember if it PX4 only. Might be ArduPilot tuning as well.

[DonLakeFlyer]

Also this is interesting, but really wonder whether the additional complexity is needed?

[HTRamsey]

I'll have to double check the tuning pages. I don't think it'll really be all that extra complex but we can see what it looks like after we're done with all the other custom cmake stuff. In my opinion this is pretty useful as I have worked with a few companies that won't use anything but LGPL

[s-lisovenko]

Agree with @HTRamsey. I also know several companies that are just thinking about abandoning QGC in favor of using only lgpl solutions.

[DonLakeFlyer]

I also know several companies that are just thinking about abandoning QGC in favor of using only lgpl solutions.

If any of those companies actually ever actually gave back to the ecosystem then I'd certainly be more interested :)

[s-lisovenko]

I also know several companies that are just thinking about abandoning QGC in favor of using only lgpl solutions.

If any of those companies actually ever actually gave back to the ecosystem then I'd certainly be more interested :)

So far these are startups and one even makes a contribution to qgc in the person of me. But no one can move on with gpl. And the prices for commercial use of qt are simply inadequate, especially since it is also subject to the qt gender license for devices, not to mention the fact that qt prohibits mixing a commercial license with an open sources.

[DonLakeFlyer]

Yeah, the Qt pricing is really kinda crap.