This adds the UI plus all necessary models and signal handling to render
discord import progress in the desktop application.
It also introduces message handling for discord chat message types.
Requires status-im/status-go#2826 to function
Co-authored with @caybro
"the user lands on the signed in app" step incorporates the following verifications (main screen is ready):
- Splash screen animation is loaded and ended.
- Banners that appear in the main screen are closed before starting other actions (secure seed phrase, connection information and update app information banners).