[web] Push changeThreadSettingsAction down to ThreadSettingsGeneralTab
Summary:
Push down changeThreadSettingsAction (and accompanying state/functionality) to ThreadSettingsGeneralTab.
Also push down the "Save" button.
In the next diff will do the same for ThreadSettingsPrivacyTab
Depends on D3840
Test Plan:
- Open ThreadSettingsModal
- Make some changes on the General tab
- Make sure that things continue to look/work as expected
Reviewers: def-au1t, palys-swm
Reviewed By: palys-swm
Subscribers: ashoat, Adrian, karol-bisztyga, yayabosh
Differential Revision: https://phabricator.ashoat.com/D3842