- API: move WifiService to mpos.net

- API: remove fonts to reduce size

- API: replace font_montserrat_28 with font_montserrat_28_compressed to reduce size

- UI: pass clicks on invisible 'gesture swipe start' are to underlying widget

- UI: only show back and down gesture icons on swipe, not on tap

- UI: double size of back and down swipe gesture starting areas for easier gestures