Review CEL rules and allow defaults

[maksymvavilov]

What

We have a naive approach to CEL validation now (they were mostly copied from existing rules of hostnames/ports). We need to reevaluate each rule and ensure they are functioning. For example: the rule on the pointer value does not work.

How

Review each rule here and evaluate.
Known problems that were reported by QA
For most of them, we could set default values. For example default interval, protocol or port.
Add test cases for each rule