chore(Schema): Add Schema-related utils

[lordrip]

Context

In order to support OneOf schemas, we need two functions:

• resolveRefIfNeeded: Resolve the $ref keyword against the definition dictionary
• weightSchemaProperties: Compare a model against a list of OneOf schemas to check what would be the applied schema.

relates: #560

[tplevko]

@lordrip Could you please explain what would the weightSchemaProperties points result used for? Having a bit difficulties to wrap my head around this

[lordrip]

Great question, I hoped for the function to be more clear, but seems it is not an easy task 😅

The motivation for the function is to compare a model against a schema to get points based on how many matches we get.

As an example:
Model

{
  refErrorHandler: {
    id: 'ref-error-handler-id',
    ref: 'reference',
  }
}

Schema

{
  type: 'object',
  properties: {
    refErrorHandler: {
      type: 'object'
      properties: {
        id: {
          type: 'string'
        },
        ref: {
          type: 'string'
        }
      }
    }
  }
}

This would match the root refErrorHandler property but also its children properties and the types, returning a high points count.

Compared to a different schema, it would return fewer points:
Schema

{
  type: 'object',
  properties: {
    refErrorHandler: {
      type: 'string'
    }
  }
}

This function will be used in an upcoming PR, but in order to reduce the diff, I'm delivering it in pieces.

[tplevko]

Thanks for the explanation!