[MM-29845] Add a new handler to allow authentication via CWS API Key (#16319)

* Add a new handler to allow authentication via CWS API Key

* Make error better

* Add tests and cases for new handler functions

* Move some code around

* Add test for GetCloudSession function

* unset the env after test completion

* Remove white space

* Change Info to Warn

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

app/authentication_test.go

@@ -26,6 +26,7 @@ func TestParseAuthTokenFromRequest(t *testing.T) {
 		{"BEARER mytoken", "", "", "mytoken", TokenLocationHeader},
 		{"", "mytoken", "", "mytoken", TokenLocationCookie},
 		{"", "", "mytoken", "mytoken", TokenLocationQueryString},
+		{"mytoken", "", "", "mytoken", TokenLocationCloudHeader},
 	}
 
 	for testnum, tc := range cases {
@@ -34,10 +35,12 @@ func TestParseAuthTokenFromRequest(t *testing.T) {
 			pathname += "?access_token=" + tc.query
 		}
 		req := httptest.NewRequest("GET", pathname, nil)
-		if tc.header != "" {
+		switch tc.expectedLocation {
+		case TokenLocationHeader:
 			req.Header.Add(model.HEADER_AUTH, tc.header)
-		}
-		if tc.cookie != "" {
+		case TokenLocationCloudHeader:
+			req.Header.Add(model.HEADER_CLOUD_TOKEN, tc.header)
+		case TokenLocationCookie:
 			req.AddCookie(&http.Cookie{
 				Name:  model.SESSION_COOKIE_TOKEN,
 				Value: tc.cookie,