[PM-11418] generator policy constraints (#11014)

* add constraint support to UserStateSubject
* add dynamic constraints
* implement password policy constraints
* replace policy evaluator with constraints in credential generation service
* add cascade between minNumber and minSpecial

Co-authored-by: Daniel James Smith <2670567+djsmith85@users.noreply.github.com>

libs/common/src/tools/state/state-constraints-dependency.ts

@@ -0,0 +1,29 @@
+import { Observable } from "rxjs";
+
+import { DynamicStateConstraints, StateConstraints } from "../types";
+
+/** A pattern for types that depend upon a dynamic set of constraints.
+ *
+ * Consumers of this dependency should track the last-received state and
+ * apply it when application state is received or emitted. If `constraints$`
+ * emits an unrecoverable error, the consumer should continue using the
+ * last-emitted constraints. If `constraints$` completes, the consumer should
+ * continue using the last-emitted constraints.
+ */
+export type StateConstraintsDependency<State> = {
+  /** A stream that emits constraints when subscribed and when the
+   *  constraints change. The stream should not emit `null` or
+   *  `undefined`.
+   */
+  constraints$: Observable<StateConstraints<State> | DynamicStateConstraints<State>>;
+};
+
+/** Returns `true` if the input constraint is a `DynamicStateConstraints<T>`.
+ *  Otherwise, returns false.
+ *  @param constraints the constraint to evaluate.
+ * */
+export function isDynamic<State>(
+  constraints: StateConstraints<State> | DynamicStateConstraints<State>,
+): constraints is DynamicStateConstraints<State> {
+  return constraints && "calibrate" in constraints;
+}