Add enough well-known types to support google/api

[coryan]

Several services use the proto messages defined in google/api. These message use more well-known types than we anticipated, including protobuf descriptors, such as google.protobuf.Type:

  // A list of all proto message types included in this API service.
  // Types referenced directly or indirectly by the `apis` are automatically
  // included.  Messages which are not referenced but shall be included, such as
  // types used by the `google.protobuf.Any` type, should be listed here by
  // name by the configuration author. Example:
  //
  //     types:
  //     - name: google.protobuf.Int32
  repeated google.protobuf.Type types = 4;

https://github.com/googleapis/googleapis/blob/29aea4190aba664659908ff5e381c830e4752502/google/api/service.proto#L107C1-L115C43

It seems that only the name is needed, which may simplify the work. Other types (e.g. google.protobuf.Struct) may need a full implementation.