feat(server): Add flag to enable schema validator for individual datasets

[nellh]

Add a schemaValidator flag to datasets that allows switching raw datasets to use the schema validator over the legacy validator.

[codecov]

Codecov Report

Attention: Patch coverage is 46.15385% with 7 lines in your changes missing coverage. Please review.

Project coverage is 44.07%. Comparing base (4e58a68) to head (38bc8e2).
Report is 6 commits behind head on master.

Files with missing lines	Patch %	Lines
...nneuro-server/src/graphql/resolvers/datasetType.ts	36.36%	7 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3140   +/-   ##
=======================================
  Coverage   44.07%   44.07%           
=======================================
  Files         593      593           
  Lines       37749    37760   +11     
  Branches     1124     1124           
=======================================
+ Hits        16636    16642    +6     
- Misses      20911    20916    +5     
  Partials      202      202           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.