Add `ConstraintValidatorInitializationContext` to the `ConstraintValidator#initialize`

Introduce the `ConstraintValidator#initialize(ConstraintDescriptor, ConstraintValidatorInitializationContext)` to provide access to more information at the constraint initialization step (e.g. ClockProvider, implementation-specific context, etc.).

Start by reviewing the ConstraintValidator API and its current initialize contract. Define the ConstraintValidatorInitializationContext and the updated initialize signature so constraint initialization can access the ClockProvider and implementation-specific context described in the issue; done means the API exposes this information consistently.

Written by the indexing model from the issue text.