[web] introduced icons for relationship action buttons

Summary:
The buttons in the relationship chat settings now have colors that are consistent with the other relationship prompt buttons found in the app.

Depends on D5100

Test Plan:
Please view the screenshots to see the before and after of the changes I made

Before:

After:
Add friend and block case:

Withdraw friend request case:

Accept and reject friend request case:

unfriend case:

unblock case:

Reviewers: atul, abosh

Reviewed By: atul

Subscribers: ashoat, tomek, atul, abosh

Differential Revision: https://phab.comm.dev/D5140