Create delete package endpoint

[codeEmpress1]

Done

• add endpoint to unregister package name

How to QA

Issue / Card https://warthogs.atlassian.net/browse/WD-6599

Fixes #

Screenshots

[webteam-app]

Demo starting at https://charmhub-io-1684.demos.haus

[steverydz]

LGTM 👍

[codecov]

Codecov Report

Merging #1684 (22082f4) into main (05c3c73) will decrease coverage by 0.01%.
The diff coverage is 42.85%.

❗ Current head 22082f4 differs from pull request most recent head 3c6ee14. Consider uploading reports for the commit 3c6ee14 to get more accurate results

@@            Coverage Diff             @@
##             main    #1684      +/-   ##
==========================================
- Coverage   42.89%   42.89%   -0.01%     
==========================================
  Files          20       20              
  Lines        1667     1674       +7     
==========================================
+ Hits          715      718       +3     
- Misses        952      956       +4     

Flag	Coverage Δ
python	42.89% <42.85%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
webapp/publisher/views.py	38.26% <42.85%> (+0.17%)	⬆️