fix(Site): Add site backup option on site drop

[AyshaHakeem]

• UI changes to opt for an offsite backup before archiving site
• Add site backup and upload backup steps to Archive Site agent job
• Create Site Backup record after archival

Agent PR

[codecov]

Codecov Report

❌ Patch coverage is 35.82090% with 43 lines in your changes missing coverage. Please review.
✅ Project coverage is 45.40%. Comparing base (0cee497) to head (5bffd24).
⚠️ Report is 33 commits behind head on develop.

Files with missing lines	Patch %	Lines
press/press/doctype/site/site.py	10.00%	27 Missing ⚠️
press/agent.py	42.85%	16 Missing ⚠️

❌ Your patch check has failed because the patch coverage (35.82%) is below the target coverage (75.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #4973      +/-   ##
===========================================
- Coverage    45.45%   45.40%   -0.05%     
===========================================
  Files          843      843              
  Lines        67356    67348       -8     
  Branches       283      284       +1     
===========================================
- Hits         30615    30581      -34     
- Misses       36713    36739      +26     
  Partials        28       28              

Flag	Coverage Δ
dashboard	72.84% <100.00%> (-0.08%)	⬇️

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