feat(opapi): Support JSON schemas as input

[xavierhamel]

Resolves KKN-290

Non-breaking proposition to support JSON Schemas.

This is now supported:

const api = new OpenApi({
  metadata: {
    title: 'Test',
    server: 'http://localhost:8080',
    version: '1.0.0',
    description: 'Description'
  },
  schemas: {
    user: {
      section: 'User',
      schema: {
        properties: {
          name: { type: 'string' },
          email: { type: 'string' },
        }
      }
    }
  }
})

api.addOperation({
  name: 'allo',
  path: '/allo',
  description: 'Ceci est une description',
  method: 'post',
  parameters: {
    'test': {
      required: true,
      description: 'Test param',
      type: 'object',
      in: 'query',
      schema: {
        properties: {
          id: {
            type: 'string',
          }
        }
      }
    }
  },
  requestBody: {
    description: 'allo',
    schema: {
      properties: {
        id: {
          type: 'string',
        }
      }
    }
  },
  response: {
    status: 200,
    description: 'Allo',
    schema: {
      properties: {
        user: api.getModelRef('user')
      }
    }
  }
})

api.exportOpenapi('./gen/')

[linear]

KKN-290 Opapi should accept JSONSchema directly