[web] Introduce ThreadSettingsRelationshipButton component

Summary:
Create a button component that dispatches a matching relationship action on click. It will be displayed in "Relationship" tab in thread settings modal on web

Test Plan: The component is not used yet. Confirm it works after introducing relationship tab in thread settings modal in next diffs.

Reviewers: tomek, atul, ashoat

Reviewed By: tomek, ashoat

Subscribers: ashoat, adrian, abosh

Differential Revision: https://phab.comm.dev/D4679