left sidebar: Add titles for remaining global filters.
left sidebar: Add titles for remaining global filters.

Fixes part of #20284.

kou/zulip,rht/zulip,kou/zulip,zulip/zulip,eeshangarg/zulip,kou/zulip,rht/zulip,zulip/zulip,eeshangarg/zulip,zulip/zulip,andersk/zulip,rht/zulip,andersk/zulip,kou/zulip,zulip/zulip,rht/zulip,eeshangarg/zulip,eeshangarg/zulip,andersk/zulip,rht/zulip,zulip/zulip,andersk/zulip,andersk/zulip,andersk/zulip,eeshangarg/zulip,zulip/zulip,kou/zulip,rht/zulip,kou/zulip,eeshangarg/zulip,zulip/zulip,rht/zulip,eeshangarg/zulip,kou/zulip,andersk/zulip