purl-next: Create the VERS JSON test suite with support for supported ecosystems

[pombredanne]

As part of the VERS standardization process and the extensions with new implmentations we need VERS JSON test suites to support for the supported ecosystems and better enforce conformance and ensure all tools behave the same.
The JSON test suite ensures that tools can use the same tests.

[pombredanne]

This has been completed:

• we first created a schema to define and validate JSON test data with purl-next: Create new JSON schema for VERS tests #6 and this PR Add schema for VERS tests package-url/vers-spec#26
• and then used the schema to create JSON test suites with purl-next: Create VERS tests for registered version schemes using JSON #7 and this PR Use VERS test definition schema for tests univers#162