[native] Add SIWEPanel to ConnectEthereum screen
Summary:
See designs. Note that this experience is still a little "rough around the edges"... proper loading state and making sure the bottom sheet is outside of the SafeAreaView will happen in later diffs.
Depends on D7843
Test Plan:
Reviewers: atul, ginsu
Reviewed By: atul
Subscribers: tomek
Differential Revision: https://phab.comm.dev/D7844