feat: Validate policy and test files with JSON schema

[oguzhand95]

No description provided.

[codecov]

Codecov Report

Merging #1526 (96e8369) into main (b6fdc81) will increase coverage by 0.15%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1526      +/-   ##
==========================================
+ Coverage   53.45%   53.61%   +0.15%     
==========================================
  Files         128      128              
  Lines       14412    14426      +14     
==========================================
+ Hits         7704     7734      +30     
+ Misses       6036     6018      -18     
- Partials      672      674       +2     

Impacted Files	Coverage Δ
internal/audit/conf.go	70.27% <ø> (ø)
internal/storage/conf.go	52.17% <ø> (ø)
schema/schema.go	0.00% <ø> (ø)
internal/storage/index/builder.go	84.76% <100.00%> (+7.57%)	⬆️
internal/verify/verify.go	76.85% <100.00%> (-6.93%)	⬇️

... and 3 files with indirect coverage changes

[charithe]

The validation step needs to be a part of the index build process. As the index builder goes through each file, it should validate them using the appropriate schema and collect any validation errors to be returned back as index build errors.

[charithe]

LGTM