Transparent background on outlined elements. Tab UIKit component.

What's Changed

• [Tech] Button: Improve ViewModel test by @robergro in #414
• [Tech] PublisherMock: add missing data and method by @robergro in #426
• [Tech-343] Switch: Update ViewModel & test by @robergro in #427
• [Fix#433] Subscribe on RunLoop.main. by @michael-zimmermann in #434
• [Tech#429] Demo app setting tab and dark mode fix by @aycil-alican in #431
• [Tab#234] The UI tab control comoponent by @michael-zimmermann in #338
• Components/outline transparent background by @LouisBorleeAdevinta in #438
• [Tech] Update DisplayedTextViewModel: Add a model, deprecate some var by @robergro in #440

Full Changelog: 0.7.5...0.7.6