Add schema-based rules for platform data of package index

[per1234]

These are the JSON schema-based rules to check the platform level data.

[codecov-commenter]

Codecov Report

Merging #200 (c1371a1) into main (9bdca8b) will increase coverage by 1.70%.
The diff coverage is 97.82%.

@@            Coverage Diff             @@
##             main     #200      +/-   ##
==========================================
+ Coverage   85.16%   86.87%   +1.70%     
==========================================
  Files          43       43              
  Lines        3391     3831     +440     
==========================================
+ Hits         2888     3328     +440     
  Misses        392      392              
  Partials      111      111              

Flag	Coverage Δ
unit	86.87% <97.82%> (+1.70%)	⬆️

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

Impacted Files	Coverage Δ
...ternal/rule/ruleconfiguration/ruleconfiguration.go	100.00% <ø> (ø)
internal/rule/rulefunction/packageindex.go	96.10% <97.82%> (+6.17%)	⬆️

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