Add unit test to validate the tag input validation change.

Author: friedkiwi

src/test/java/de/rwth/idsg/steve/web/validation/IdTagValidatorTest.java

@@ -91,9 +91,20 @@ public void testColon() {
         Assertions.assertTrue(validator.isValid("VID:00XXXXXXXXXX", null));
     }
 
+    @Test
+    public void testPoundSign() {
+        Assertions.assertTrue(validator.isValid("#test", null));
+        Assertions.assertTrue(validator.isValid("test#", null));
+        Assertions.assertTrue(validator.isValid("te##st", null));
+
+        // Tag provided by Webasto charge points
+        // https://github.com/steve-community/steve/pull/1322
+        Assertions.assertTrue(validator.isValid("#FreeCharging", null));
+    }
+
     @Test
     public void testCombined() {
-        Assertions.assertTrue(validator.isValid("1t.E-S_:t20", null));
+        Assertions.assertTrue(validator.isValid("1t.E-S_:t20#", null));
     }
 
 }