[web] Disable thick thread entries from showing up in the history modal as history entries

Summary:
This disables thick thread entries from showing up in the history modal

Depends on D13350

Test Plan: Tested on local webapp. Keyserver history entries still showed up fine but thick thread entries did not

Reviewers: ashoat, tomek, marcin

Reviewed By: ashoat

Differential Revision: https://phab.comm.dev/D13354