[RFC] feat: add events proto

[elianiva]

1. MouseScroll parameternya apa aja? possible ref: Delete publicroutes, privateroutes, and finalroutes #92
2. Pake present tense atau past tense? (MouseClickRequest vs MouseClickedRequest)
3. Mouse click biarin per-click atau per mouse-up / mouse-down ? disini, di bagian click features ada field buat ngitung seberapa lama user nahan mouse-down soalnya, tapi sekarang yg di-emit itu baru keydown doang jadi ga bisa dihitung lamanya

also, tadi pas buka filenya dapet error Import "enums.proto" was not found or had errors., gatau beneran error atau ngga

[elianiva]

enumnya aku kasih suffix _BUTTON soalnya conflict sama enum Direction.