Fixed semver, fixed reporting

[alanisaac]

Related Issue:

• part of Metaschemas: create JSON schema definitions for OCSF schemas #735
• Additional metaschemas #867 (comment)
• Correction of version values in @deprecated tags #883

Description of changes:

This PR does three things:

• Cleans up one leftover usage of "v" as a prefix in semver versions in the dictionary.json schema
• Removes the v? prefix from the semver regex to disallow it in future schemas
• Changes the way the event schema is defined for events.

The last bullet is a bit more complex:

• There are two ways to achieve schema extensions in JSON schemas that have constraints on them: additionalProperties: false along with redeclaring the inherited properties OR unevaluatedProperties: false.
• See https://json-schema.org/understanding-json-schema/reference/object#extending for more details on these patterns
• Originally I went with the unevaluatedProperties pattern, as it avoids redeclaring property names as in this PR, but I found that validation messages were wonky in the schema validation library I used.
• When the unevaluatedProperties does not pass on any nested attribute of the inherited schema, it would flag the entire schema (rather than the attribute) as being wrong. e.g. in the semver issue I am fixing in this PR...
  • An error message with unevaluatedProperties would say dictionary.json has unexpected attribute attributes because a sub-sub-sub-sub.... schema of attributes did not pass
  • An error message with additionalProperties like in this PR will explicitly point to the field that is wrong:

  File at events/findings/security_finding.json does not pass metaschema validation. Error: 'v1.1.0' does not match '^(0|[1-9]\\d*)\\.(0|[1-9]\\d*)\\.(0|[1-9]\\d*)(?:-((?:0|[1-9]\\d*|\\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\\.(?:0|[1-9]\\d*|\\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\\+([0-9a-zA-Z-]+(?:\\.[0-9a-zA-Z-]+)*))?$' at JSON path: '[email protected]'
  

TL;DR: while the new pattern in this PR is more verbose and repeats information, it produces much better error messages when schemas fail on validation, which I think is more important.

[floydtree]

awesome! thank you.