Validate nodeinfo response by schema (#21395)

* add json-schema to :test in Gemfile

* Create node_info_2.0_schema.json

* test match_response_schema

* Create match_response_schema.rb

* Update nodeinfo_controller_spec.rb

* Rename spec/support/node_info_2.0_schema.json to spec/support/schema/node_info_2.0_schema.json

* Update match_response_schema.rb

* cleanup

* additionally validate the json schema itself

disable throwing errors

test the schema matcher

* rename nodeinfo schema to nodeinfo_2.0

* use Rails.root.join to construct the path

* prettify json

* sync Gemfile.lock

spec/controllers/well_known/nodeinfo_controller_spec.rb

@@ -27,6 +27,8 @@ describe WellKnown::NodeInfoController, type: :controller do
 
       json = body_as_json
 
+      expect({ "foo" => 0 }).not_to match_json_schema("nodeinfo_2.0")
+      expect(json).to match_json_schema("nodeinfo_2.0")
       expect(json[:version]).to eq '2.0'
       expect(json[:usage]).to be_a Hash
       expect(json[:software]).to be_a Hash