[CX] Character classes unclosed properly causes the query to fail

In some case, for example, providing a pattern such as [a-b0-9.* without properly closing the bracket, would result in a failure that the provided pattern is invalid. However, this is a valid pattern, in the above case, the open (unclosed) bracket should be escaped as this is a literal and not a character class case.

Such cases should be handled properly, as the above could be a valid file name that is [a-b0-9.json for example.