Dark theme, UI elements unification, UX enhancements

[bfmvsa]

THIS IS DRAFT, please do not merge since some parts of this huge PR is still in progress.

Please Note: I didn't test these changes in Windows, because I do not have this OS, if there are any problems please send me screenshots.

I'm going to write detailed docs for all changes. But for now this short description is:
Mostly all changes are cosmetic, the biggest UX changes were in Failsafe tab (simplified visual part).
In this PR I use bootstrap sass framework for unification UI elements like buttons, tables, lists, etc. Also, it supports dark themes out of the box. However, developers still can use regular CSS files as they used to be.

Apart from Dark/Light theme, I've added an inverted sidebar & header according to this reasonable request.

Some screenshots:

[27 October '24]

Ready for testing tabs:

1. Welcome
2. Mission Control
3. Firmware Flasher
4. SITL [25 October '24]
5. Status
6. Calibration
7. Mixer [27 October '24]
8. Outputs [27 October '24]
9. Ports
10. Configuration
11. Failsafe
12. Tuning [24 October '24]
13. Advanced Tuning
14. Programming [24 October '24]
15. Receiver
16. Modes
17. Adjustments
18. GPS
19. Alignment Tool
20. OSD [25 October '24]
21. LED Strip
22. Sensors
23. Tethered Logging
24. Blackbox
25. CLI
26. Options

[bfmvsa]

@trailx This is still a standalone app, when I say "mobile friendly" I mean it looks ok and is usable on narrow screens. In other words, It has a responsive design.

[trailx]

@bfmvsa I gotcha, I wasn't sure if there was something I had missed. There are often times when I use it half screen, so just being more responsive to window size will be nice!

Since you're in there, one idea that came up in a discussion was creating a button in the blackbox tab that would put the FC into MSC mode. Betaflight has this, and it's handy rather than having to look it up on GitHub every time. This seems like a relatively easy add and would bring more attention to the MSC function. Since you're working on the UI, you seemed like the best person to bring this up to. Thanks for the consideration!

[bfmvsa]

@trailx It looks like somebody was trying to add this button (at least it is presented on the tab). But if I am not mistaken this button is not working (always disabled and there are no any click handlers for this button), also this button is added only for SD cards, need it also for onboard dataflash chip.
As a part of this huge PR I decided to not change the current logic a lot, but in the future your suggestion will be implemented, this is already in my todo list :)

[bfmvsa]

[Update] Reworked Tuning tab according to the new UI

[bfmvsa]

@sensei-hacker @trailx Just updated the PR, now Everything is ready from my side. I probably will do some commits, but in general, it is ready for testing.