[🐛 Bug]: CEL rule builder fails to parse "namspace == 'some_namespace'"

[shahargl]

Describe the bug

To Reproduce
Any CEL with "namespace" in it.

** Root cause **
This is happen because the underlying library (react-querybuilder) uses the official CEL spec, in which "namespace" is a reserved key word:
https://github.com/google/cel-spec/blob/master/doc/langdef.md

** possible workaround **
the fix for that would be the wrap/unwrapp the namespace keyword before/after validation, but its not trivial.