'key' is now a KeyWord

As unit tests contains the 'key' word, they are invalid.
The 'key' word is now replaced by 'ref'.

Author: Muldec

testing/integration-neo4j/src/test/resources/parsing/patterns/Patterns.txt

@@ -1167,7 +1167,7 @@ Cypher file: FILE(0,751)
                                   CypherPropertyKeyNameImpl(PROPERTY_KEY_NAME)(682,685)
                                     CypherSymbolicNameStringImpl(SYMBOLIC_NAME_STRING)(682,685)
                                       CypherUnescapedSymbolicNameStringImpl(UNESCAPED_SYMBOLIC_NAME_STRING)(682,685)
-                                        PsiElement(identifier)('key')(682,685)
+                                        PsiElement(identifier)('ref')(682,685)
                                   PsiElement(:)(':')(685,686)
                                   CypherExpressionImpl(EXPRESSION)(687,694)
                                     CypherStringLiteralImpl(STRING_LITERAL)(687,694)