settings UI: Fix settings sidebar.
settings UI: Fix settings sidebar.

Fixes broken settings page on continuous use of tab key.
Sets settings sidebar visibility to hidden when not visible.
Fixes: #7982.

rishig/zulip,timabbott/zulip,rht/zulip,brainwane/zulip,rishig/zulip,jackrzhang/zulip,punchagan/zulip,showell/zulip,rishig/zulip,rishig/zulip,synicalsyntax/zulip,jackrzhang/zulip,kou/zulip,synicalsyntax/zulip,jackrzhang/zulip,rht/zulip,shubhamdhama/zulip,hackerkid/zulip,rishig/zulip,showell/zulip,zulip/zulip,jackrzhang/zulip,rht/zulip,jackrzhang/zulip,rishig/zulip,dhcrzf/zulip,kou/zulip,punchagan/zulip,showell/zulip,synicalsyntax/zulip,synicalsyntax/zulip,showell/zulip,synicalsyntax/zulip,showell/zulip,andersk/zulip,shubhamdhama/zulip,rht/zulip,punchagan/zulip,tommyip/zulip,shubhamdhama/zulip,eeshangarg/zulip,synicalsyntax/zulip,tommyip/zulip,punchagan/zulip,brainwane/zulip,zulip/zulip,timabbott/zulip,hackerkid/zulip,dhcrzf/zulip,andersk/zulip,hackerkid/zulip,kou/zulip,eeshangarg/zulip,kou/zulip,eeshangarg/zulip,dhcrzf/zulip,andersk/zulip,tommyip/zulip,zulip/zulip,dhcrzf/zulip,eeshangarg/zulip,zulip/zulip,showell/zulip,andersk/zulip,shubhamdhama/zulip,eeshangarg/zulip,timabbott/zulip,hackerkid/zulip,rht/zulip,tommyip/zulip,andersk/zulip,zulip/zulip,dhcrzf/zulip,eeshangarg/zulip,eeshangarg/zulip,synicalsyntax/zulip,brainwane/zulip,zulip/zulip,hackerkid/zulip,jackrzhang/zulip,punchagan/zulip,kou/zulip,tommyip/zulip,rishig/zulip,punchagan/zulip,timabbott/zulip,shubhamdhama/zulip,dhcrzf/zulip,zulip/zulip,tommyip/zulip,hackerkid/zulip,tommyip/zulip,brainwane/zulip,kou/zulip,hackerkid/zulip,andersk/zulip,andersk/zulip,punchagan/zulip,rht/zulip,brainwane/zulip,kou/zulip,timabbott/zulip,dhcrzf/zulip,rht/zulip,timabbott/zulip,showell/zulip,brainwane/zulip,jackrzhang/zulip,timabbott/zulip,shubhamdhama/zulip,brainwane/zulip,shubhamdhama/zulip