fix: Rewrite upper right document search box

[ekr]

This is a fix to the problem where the first item in the dropdown is auto-selected and then when you hit return you go to that rather than searching for what's in the text field.

It appears to be challenging to get this behavior with select2, so this is actually a rewrite of the box with explicit behavior. As a side effect, the draft names actually render a bit better.

Fixes #10358

[jennifer-richards]

Thanks for this. I think it needs a couple tweaks before we can merge it.

The draft names are all cut off by the right-hand side of the window, showing in many cases the least informative part of draft names. The old wrapped names were a little awkward, but this seems less usable to me.

Also, we should extract the JS code into a module rather than inlining it in base.html. This commit shows what's needed, but I'd be happy to do that refactor if you prefer.

[ekr]

Updated per review comments.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.39%. Comparing base (d50e812) to head (2cbc378).
⚠️ Report is 40 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #10538      +/-   ##
==========================================
- Coverage   88.39%   88.39%   -0.01%     
==========================================
  Files         326      330       +4     
  Lines       43813    44255     +442     
==========================================
+ Hits        38727    39117     +390     
- Misses       5086     5138      +52     

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