feat: Support IIIF Image's API HEAD requests (DEV-4072)

[siers]

HEAD requests should return the status code without the body content. E2E Tests included.

[linear]

DEV-4072 Support HEAD requests for IIIF URLs in SIPI

[codecov]

Codecov Report

Attention: Patch coverage is 12.50000% with 7 lines in your changes missing coverage. Please review.

Project coverage is 22.6%. Comparing base (83c2c94) to head (62dfd22).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/SipiHttpServer.cpp	12.5%	3 Missing and 4 partials ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
src/SipiHttpServer.cpp	21.0% <12.5%> (+<0.1%)	⬆️

... and 2 files with indirect coverage changes