Generic422 error rename to be more explicit

[XunliYang]

Generic422 error is actually not generic, but a specific error for network slide booking
To be more explicit, it could be renamed to "NetworkSliceBooking422".

also there are several reasons listed in the example which seem worth having their own 422 error : service area is not supported, resources are insufficient - for better problem understand, rather than having them in the same error.

Could be done for the next release.

Originally posted by @tanjadegroot in #78 (comment)

[XunliYang]

Optional changes:

NetworkSliceBooking422:
  description: Unprocessable Content
  headers:
    x-correlator:
      $ref: "#/components/headers/x-correlator"
  content:
    application/json:
      schema:
        allOf:
          - $ref: "#/components/schemas/ErrorInfo"
          - type: object
            properties:
              status:
                enum:
                  - 422
              code:
                enum:
                  - NETWORK_SLICE_BOOKING.SERVICEAREA_NOT_SUPPORTED
                  - NETWORK_SLICE_BOOKING.RESOURCES_INSUFFICIENT
      examples:
        NETWORK_SLICE_BOOKING_422_SERVICE_AREA_NOT_SUPPORTED:
          description: Business logic exception use when the requested service area is not supported
          value:
            status: 422
            code: NETWORK_SLICE_BOOKING.SERVICEAREA_NOT_SUPPORTED
            message: The requested service area is not supported.
        NETWORK_SLICE_BOOKING_422_RESOURCES_INSUFFICIENT:
          description: Business logic exception use when the left resources are not sufficient for the requested slice resources
          value:
            status: 422
            code: NETWORK_SLICE_BOOKING.RESOURCES_INSUFFICIENT
            message: The left resources are not sufficient for the requested slice resources.