navbar: Fix clickable area between sub_count and narrow_description.
navbar: Fix clickable area between sub_count and narrow_description.

Previously, there was a small dead spot in the click area between the
sub_count and narrow_description, such that the mouse cursor would
switch from pointer to the default.

This commit corrects the dead spot by adjusting the margins and styles
on navbar elements.

This should be workable, but there is scope for improvement especially
given that the current margins and paddings are messy and not very
semantic.

The end result is that the entire navbar becomes a smooth, clickable
region.

timabbott/zulip,eeshangarg/zulip,rht/zulip,andersk/zulip,andersk/zulip,eeshangarg/zulip,showell/zulip,zulip/zulip,eeshangarg/zulip,andersk/zulip,brainwane/zulip,synicalsyntax/zulip,shubhamdhama/zulip,synicalsyntax/zulip,showell/zulip,brainwane/zulip,punchagan/zulip,shubhamdhama/zulip,zulip/zulip,timabbott/zulip,andersk/zulip,timabbott/zulip,kou/zulip,showell/zulip,shubhamdhama/zulip,punchagan/zulip,synicalsyntax/zulip,hackerkid/zulip,kou/zulip,zulip/zulip,eeshangarg/zulip,kou/zulip,showell/zulip,rht/zulip,kou/zulip,brainwane/zulip,synicalsyntax/zulip,shubhamdhama/zulip,hackerkid/zulip,punchagan/zulip,showell/zulip,eeshangarg/zulip,andersk/zulip,brainwane/zulip,brainwane/zulip,kou/zulip,andersk/zulip,zulip/zulip,zulip/zulip,rht/zulip,rht/zulip,zulip/zulip,kou/zulip,brainwane/zulip,synicalsyntax/zulip,rht/zulip,eeshangarg/zulip,hackerkid/zulip,timabbott/zulip,shubhamdhama/zulip,zulip/zulip,hackerkid/zulip,hackerkid/zulip,andersk/zulip,eeshangarg/zulip,shubhamdhama/zulip,timabbott/zulip,kou/zulip,showell/zulip,timabbott/zulip,hackerkid/zulip,synicalsyntax/zulip,timabbott/zulip,brainwane/zulip,punchagan/zulip,punchagan/zulip,shubhamdhama/zulip,showell/zulip,rht/zulip,punchagan/zulip,rht/zulip,hackerkid/zulip,punchagan/zulip,synicalsyntax/zulip