Popup improvements

[klutvott123]

Some improvements to the popup menu and the confirmation page functionality.

The popup menu can now be opened by long pressing enter on the main menu and on the page view. The menu is now created on demand so that we can populate it with different items depending on the uiState we're in.

Now we can do this:

and this:

Made a new state uiStatus.confirm for the confirmation dialogue.
Added a confirmation dialogue for downloading vtx tables too.

Changed the behaviour a little so that after calibrating the accelerometer or downloading vtx tables the script will return to the previous uiState on completion. This just makes the user experience a little nicer. The old behaviour was that it returned to the main menu.

Removed getSensorValue and simplified modelActive a lot. This code was a lot more complicated than it had to be.

Moved all lcd writing to ui.lua. ui_init.lua and all the functions called by it will now return a table containing a function and a string.

Test version here:
betaflight-tx-lua-scripts_1.5.0.zip

[haslinghuis]

What kind of language 😆 LGTM