Add payment menu

java/AndroidManifest.xml

java/res/drawable/dollar_sign.xml

java/res/values/strings-uix.xml

...src/org/futo/inputmethod/latin/payment/PaymentActivity.kt

...futo/inputmethod/latin/payment/PaymentCompleteActivity.kt

...src/org/futo/inputmethod/latin/uix/settings/Components.kt

java/src/org/futo/inputmethod/latin/uix/settings/Hooks.kt

.../futo/inputmethod/latin/uix/settings/SettingsNavigator.kt

...nputmethod/latin/uix/settings/pages/AdvancedParameters.kt

.../futo/inputmethod/latin/uix/settings/pages/DevSettings.kt

...src/org/futo/inputmethod/latin/uix/settings/pages/Help.kt

...src/org/futo/inputmethod/latin/uix/settings/pages/Home.kt

.../org/futo/inputmethod/latin/uix/settings/pages/Payment.kt

java/src/org/futo/inputmethod/latin/uix/theme/Theme.kt

native/jni/src/defines.h