feat(server): handle head method

[james-d-elliott]

This implements some HEAD method handlers for various static resources and the /api/health endpoint.

[authelia]

Artifacts

These changes are published for testing on Buildkite, DockerHub and GitHub Container Registry.

Docker Container

• docker pull authelia/authelia:feat-head-resp
• docker pull ghcr.io/authelia/authelia:feat-head-resp

[codecov]

Codecov Report

Merging #5003 (9370271) into master (f68e5cf) will increase coverage by 0.29%.
The diff coverage is 69.33%.

❗ Current head 9370271 differs from pull request most recent head 3f20e54. Consider uploading reports for the commit 3f20e54 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5003      +/-   ##
==========================================
+ Coverage   68.22%   68.51%   +0.29%     
==========================================
  Files         283      283              
  Lines       20914    20958      +44     
  Branches      443      443              
==========================================
+ Hits        14268    14359      +91     
+ Misses       5875     5823      -52     
- Partials      771      776       +5     

Flag	Coverage Δ
backend	68.96% <69.33%> (+0.31%)	⬆️
frontend	63.20% <ø> (+0.04%)	⬆️

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

Impacted Files	Coverage Δ
internal/handlers/handler_oidc_wellknown.go	5.55% <0.00%> (-22.23%)	⬇️
internal/server/template.go	60.90% <55.26%> (+16.82%)	⬆️
internal/server/asset.go	69.71% <73.33%> (-0.04%)	⬇️
internal/server/handlers.go	93.13% <100.00%> (+6.97%)	⬆️
internal/handlers/handler_status.go	25.00% <0.00%> (-75.00%)	⬇️
web/src/services/SignOut.ts	100.00% <0.00%> (+14.28%)	⬆️