Update the rest of the parameters descriptions, add hover-over to notifictaions, and fix inconsistencies in variables and descriptions

Author: renetapopova

modules/ROOT/pages/errors/gql-errors/50N21.adoc

@@ -3,6 +3,13 @@
 == Status description
 error: general processing exception - no such schema descriptor. The `{ <<schemaDescrType>> }` was not found for `{ <<schemaDescr>> }`. Verify that the spelling is correct.
 
+For example:
+
+[source, shell]
+----
+error: general processing exception - no such schema descriptor. The label property existence constraint was not found for '(:Label1 {prop1})'. Verify that the spelling is correct.")
+----
+
 ifndef::backend-pdf[]
 [discrete.glossary]
 == Glossary