[landing] Style SIWE page a bit better and improve UX
Summary:
- Get rid of the button and just open the connect modal right away
- Get the styling to match what our WebView looks like
Test Plan:
Note that this is combination with several other changes on the native side that will be coming in future diffs (introduction of bottom-sheet, some styling) :
Reviewers: atul
Reviewed By: atul
Subscribers: tomek
Differential Revision: https://phab.comm.dev/D6003