refactor: Replace spray json with zio-json for FileMetadataSipiResponse

[seakayone]

Pull Request Checklist

Task Description/Number

Spray json is able to parse 42.0 as an Int, zio-json is more strict fails, see also zio/zio-json#1049. Hence, we have to add a custom decoder for Int.

PR Type

• build/chore: maintenance tasks (no production code change)
• docs: documentation changes (no production code change)
• feat: represents new features
• fix: represents bug fixes
• perf: performance improvements
• refactor: represents production code refactoring
• test: adding or refactoring tests (no production code change)

Basic requirements for bug fixes and features

• Tests for the changes have been added
• Docs have been added / updated

Does this PR introduce a breaking change?

• Yes

Does this PR change client-test-data?

• Yes

[codecov]

Codecov Report

Attention: 56 lines in your changes are missing coverage. Please review.

Comparison is base (ff9df5f) 11.63% compared to head (f31e000) 11.64%.
Report is 7 commits behind head on main.

Files	Patch %	Lines
...s/v2/responder/valuemessages/ValueMessagesV2.scala	0.00%	22 Missing ⚠️
.../org/knora/webapi/store/iiif/api/SipiService.scala	0.00%	9 Missing ⚠️
...knora/webapi/store/iiif/impl/SipiServiceLive.scala	0.00%	5 Missing ⚠️
...ra/webapi/responders/v2/ResourcesResponderV2.scala	0.00%	4 Missing ⚠️
...c/main/scala/org/knora/webapi/core/AppServer.scala	0.00%	2 Missing ⚠️
...vsearch/prequery/GravsearchQueryOptimisation.scala	0.00%	2 Missing ⚠️
...ora/webapi/responders/admin/SipiResponderADM.scala	0.00%	2 Missing ⚠️
...org/knora/webapi/routing/admin/FilesRouteADM.scala	0.00%	2 Missing ⚠️
...la/org/knora/webapi/routing/v2/SearchRouteV2.scala	0.00%	2 Missing ⚠️
.../webapi/store/iiif/IIIFRequestMessageHandler.scala	0.00%	2 Missing ⚠️
... and 4 more

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2941   +/-   ##
=======================================
  Coverage   11.63%   11.64%           
=======================================
  Files         247      246    -1     
  Lines       22922    22887   -35     
=======================================
- Hits         2668     2666    -2     
+ Misses      20254    20221   -33     

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