pdcl-15166: fix ajv hoist issue for non-node environments

[brenthosie]

Description

ajv is already a regular dependency of reactor-validator (not a peer dep), npm guarantees it gets installed nested under node_modules/@adobe/reactor-validator/node_modules/ajv.

If validateSchema.js does require('ajv/dist/core') directly instead of going through ajv-draft-04, that require resolves relative to reactor-validator's own location — finding the nested ajv@8 correctly, regardless of what version of ajv the consumer has at their top level.

The indirection through ajv-draft-04 is what breaks things: it's a separately-hoisted package with its own (broken) resolution scope. Cutting it out means the ajv require never leaves reactor-validator's own module boundary.

Related Issue

https://jira.corp.adobe.com/browse/PDCL-15166

Motivation and Context

When attempting to integrate reactor-validator into Lens, the Lens project needed to install ajv8 as a direct dependency even though the project doesn't use it outside of calling reactor-validator.

How Has This Been Tested?

New tests added to test that we are draft 4 compliant in reactor-validator.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.