feat(policy): DSPX-2754 decompose subject mapping operators (#3335)

Split the all-in-one SubjectMappingOperatorEnum into independent axes:
ConditionComparisonOperatorEnum (EQUALS/CONTAINS/STARTS_WITH/ENDS_WITH) and
ConditionQuantifierEnum (ANY/ALL/NONE), plus a case_insensitive flag on
Condition. The legacy operator field is deprecated and retained so the service
layer can normalize old payloads for backward compatibility.

Apply the same comparison model to DynamicValueResolver (comparison +
case_insensitive) and drop the unreleased DynamicValueOperatorEnum. The dynamic
match is inherently existential over the selector-resolved entity values, so it
carries no quantifier. This also removes the confusing "inversion" wording
raised in review.

Proto plus regenerated code and docs only. Normalization, evaluation, and
cross-field validation land in the service PR #3568.

Signed-off-by: Krish Suchak <suchak.krish@gmail.com>

Author: alkalescent