Zulip: Fix mobile view search bar styling

[synicalsyntax]

• [x] Fix broken search bar height (it's overflowing) // Fixed in 21d537d
• [x] Fix the the streams sidebar icon's border being to the left of its entire background
• [ ] Fix cramping of cancel/search icon in search bar while narrowed to a stream and topic
• [ ] Home icon background should match the streams/user sidebar icon backgrounds in night mode for consistency with day mode background coloring

Tagging @skunkmb since he recently did work on the search bar.

[zulipbot]

Hello @zulip/server-search members, this issue was labeled with the "area: search" label, so you may want to check it out!

[marco]

@synicalsyntax By the way, I think that the overflowing search bar was solved in 21d537d3bd58f3fd0660db1483fcd02f7183cc89, but correct me if you're referring to a different issue. Other than that, I think that the rest of the issues that you listed still need fixing. :+1:

[alexandraciobica]

Hi. I would like to work on the two remaining issues here. I saw that the discussion is quite old, but I tested and the issues are still there.

[timabbott]

@alexandraciobica great! I think we should hold off on this issue for about a week, since https://github.com/zulip/zulip/pull/11894 will likely merge conflict, but after that I'd love to see this happen.

Let me know if you're having trouble finding a good issue to work on now -- I can point out a few good ones.

[alexandraciobica]

@timabbott Great! I will wait until the other issue is merged.

I would definitely need some help in finding an issue :D Thank you!