Added koin, databinding and navigation components

Converted App class and Main activity to Kotlin. With that refactored fields within App class to allow lazy initialization

BEWARE: at this point the navigation is very much broken, won't let you anywhere beyond home screen

app/src/main/java/com/topjohnwu/magisk/di/ViewModelsModule.kt

@@ -0,0 +1,10 @@
+package com.topjohnwu.magisk.di
+
+import com.topjohnwu.magisk.ui.MainViewModel
+import org.koin.androidx.viewmodel.dsl.viewModel
+import org.koin.dsl.module
+
+
+val viewModelModules = module {
+    viewModel { MainViewModel() }
+}