adopt to modern Django

[jrief]

Description

• Replace re_path against path
• Use admin.decorators.action to mark actions
• Remove dysfunctional jQuery function $.actions()

Checklist

• [x] I have opened this pull request against master
• [ ] I have added or modified the tests when changing logic
• [x] I have followed the conventional commits guidelines to add meaningful information into the changelog
• [x] I have read the contribution guidelines and I have joined #workgroup-pr-review on Slack to find a “pr review buddy” who is going to review my pull request.

[jrief]

This pull request will turn green after #1340 has been merged.

[codecov[bot]]

Codecov Report

Merging #1341 (8303715) into master (0bbbe88) will decrease coverage by 0.22%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1341      +/-   ##
==========================================
- Coverage   72.40%   72.19%   -0.22%     
==========================================
  Files          72       72              
  Lines        3269     3262       -7     
  Branches      532      541       +9     
==========================================
- Hits         2367     2355      -12     
- Misses        735      740       +5     
  Partials      167      167              

Impacted Files	Coverage Δ
filer/admin/folderadmin.py	71.72% <100.00%> (-0.15%)	:arrow_down:
filer/templatetags/filer_admin_tags.py	88.60% <100.00%> (ø)

... and 2 files with indirect coverage changes

[marksweb]

@jrief could you rebase this now that I've merged #1340 please?