[native] Create a modal where invite links are displayed

Summary:
In this modal we display a link and allow user to copy it.

Depends on D7728

Test Plan: Display a modal and click copy button - a pasteboard should contain the link.

Reviewers: bartek, kamil, inka

Reviewed By: kamil, inka

Subscribers: ted, ashoat, atul

Differential Revision: https://phab.comm.dev/D7730