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/common/src/vault/linked-field-option.decorator.ts

@@ -0,0 +1,27 @@
+import { LinkedIdType } from "./enums";
+import { ItemView } from "./models/view/item.view";
+
+export class LinkedMetadata {
+  constructor(readonly propertyKey: string, private readonly _i18nKey?: string) {}
+
+  get i18nKey() {
+    return this._i18nKey ?? this.propertyKey;
+  }
+}
+
+/**
+ * A decorator used to set metadata used by Linked custom fields. Apply it to a class property or getter to make it
+ *    available as a Linked custom field option.
+ * @param id - A unique value that is saved in the Field model. It is used to look up the decorated class property.
+ * @param i18nKey - The i18n key used to describe the decorated class property in the UI. If it is null, then the name
+ *    of the class property will be used as the i18n key.
+ */
+export function linkedFieldOption(id: LinkedIdType, i18nKey?: string) {
+  return (prototype: ItemView, propertyKey: string) => {
+    if (prototype.linkedFieldOptions == null) {
+      prototype.linkedFieldOptions = new Map<LinkedIdType, LinkedMetadata>();
+    }
+
+    prototype.linkedFieldOptions.set(id, new LinkedMetadata(propertyKey, i18nKey));
+  };
+}