image/tree: Print longest names first and use full width

[vvoland]

When printing image names, sort them by length and print the longest first. This also allows them to use a full terminal width because they are not printed alongside other columns.

Before

After

- Description for the changelog

Fix `docker images --tree` unnecessary truncating long image names when multiple names are available

- A picture of a cute animal (not mandatory but encouraged)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 12 lines in your changes missing coverage. Please review.

Project coverage is 59.45%. Comparing base (f4a68da) to head (708b732).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5757      +/-   ##
==========================================
- Coverage   59.47%   59.45%   -0.02%     
==========================================
  Files         346      346              
  Lines       29367    29375       +8     
==========================================
  Hits        17465    17465              
- Misses      10929    10937       +8     
  Partials      973      973