[web] Fix long names in displaying incorrectly in the ChatMessageListContainers header

Summary:
issue: https://linear.app/comm/issue/ENG-3070/fix-long-names-displaying-incorrectly-in-the-chatmessagelistcontainers
Long names used to display incorrectly: the white space would wrap around, and long names with no spaces would go off the screen. this diff fixes that. note that since D6745 in this header we only show the chats name

Test Plan: Run web app, checked thatt long names display correctly in the ChatMessageListContainers header (and so do short names)

Reviewers: michal, kuba, bartek

Reviewed By: bartek

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D6851