[Validator] add deprecation log (#12700)

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | yes
| Tests pass?   | yes
| Fixed tickets | #12700 
| License       | MIT
| Doc PR        | 

This adds depreciation note for ConstraintViolation::getMessageParameters() and ConstraintViolation::getMessagePluralization() methods.
"was deprecated"

Can you also add "()" after the method name?