[web] Modify Label component so that the content can be broken in any place

Summary:
We need to handle long content (e.g. usernames). We should be able to see the full content instead of having an ellipsis, so setting this prop makes the most sense.

Test Plan: Render a label with modified style and check if it looks ok.

Reviewers: def-au1t, atul, benschac

Reviewed By: atul

Subscribers: ashoat, Adrian, yayabosh

Differential Revision: https://phab.comm.dev/D4264