dials.image_viewer: remove basis vector display

[dagewa]

This was found to be problematic and not useful, so this PR removes it. As a side-effect, the settings panel is also now a couple of rows shorter, which helps with #2142

[codecov]

Codecov Report

Merging #2484 (1fab9f1) into main (4b86bb6) will increase coverage by 0.08%.
Report is 4 commits behind head on main.
The diff coverage is 72.38%.

❗ Current head 1fab9f1 differs from pull request most recent head 0178607. Consider uploading reports for the commit 0178607 to get more accurate results

@@            Coverage Diff             @@
##             main    #2484      +/-   ##
==========================================
+ Coverage   78.61%   78.69%   +0.08%     
==========================================
  Files         607      608       +1     
  Lines       74440    74477      +37     
  Branches    10134    10131       -3     
==========================================
+ Hits        58518    58611      +93     
+ Misses      13759    13700      -59     
- Partials     2163     2166       +3