add saved spaces on saved_objects route

Closes https://gitlab.com/JOGL/JOGL/-/issues/903

I noticed we didn't have tests for programs, should we add for programs and newly added spaces, or it's not necessary?

Jogl-Backend/spec/controllers/api/users_controller_spec.rb

describe '#saved' do
      before do
        @project = create(:project, creator_id: @user.id)
        @community = create(:community, creator_id: @user.id)
        @need = create(:need, project_id: @project.id, user_id: @user.id)
        @challenge = create(:challenge)
        @user2 = create(:confirmed_user)
        @user3 = create(:confirmed_user)
        @user.owned_relations.create(resource: @project, saved: true)
        @user.owned_relations.create(resource: @community, saved: true)
        @user.owned_relations.create(resource: @need, saved: true)
        @user.owned_relations.create(resource: @challenge, saved: true)
        @user.owned_relations.create(resource: @user2, saved: true)
        @user.owned_relations.create(resource: @user3, saved: true)
      end

      it 'should get the collection of saved items' do
        get :saved_objects
        json_response = JSON.parse(response.body)
        expect(response).to have_http_status :ok
        expect(json_response['projects'].count).to eq 1
        expect(json_response['projects'][0]['id']).to eq @project.id

        expect(json_response['needs'].count).to eq 1
        expect(json_response['needs'][0]['id']).to eq @need.id

        expect(json_response['users'].count).to eq 2
        expect(json_response['users'][0]['id']).to eq @user2.id
        expect(json_response['users'][1]['id']).to eq @user3.id

        expect(json_response['challenges'].count).to eq 1
        expect(json_response['challenges'][0]['id']).to eq @challenge.id

        expect(json_response['communities'].count).to eq 1
        expect(json_response['communities'][0]['id']).to eq @community.id
      end
    end