Assign ownership to many libs files (#6928)

Assign ownership to many of the remaining libs/common files.

Criteria for ownership:
* Files used by a single team, is now owned by that team.
* Files related to a domain owned by a team is now owned by that team.
* Where ownership is unclear the "lowest level" service takes ownership.

libs/angular/src/admin-console/validators/not-allowed-value-async.validator.ts

@@ -0,0 +1,21 @@
+import { AbstractControl, AsyncValidatorFn, ValidationErrors } from "@angular/forms";
+
+export function notAllowedValueAsync(
+  valueGetter: () => Promise<string>,
+  caseInsensitive = false
+): AsyncValidatorFn {
+  return async (control: AbstractControl): Promise<ValidationErrors | null> => {
+    let notAllowedValue = await valueGetter();
+    let controlValue = control.value;
+    if (caseInsensitive) {
+      notAllowedValue = notAllowedValue.toLowerCase();
+      controlValue = controlValue.toLowerCase();
+    }
+
+    if (controlValue === notAllowedValue) {
+      return {
+        notAllowedValue: true,
+      };
+    }
+  };
+}