feat: 🎸 create manage custom scopes route and view (#2359)

* feat: 🎸 create manage custom scopes route and view

✅ Closes: https://hashicorp.atlassian.net/browse/ICU-13881

---------

Co-authored-by: Zhihe Li <zhihe.li@hashicorp.com>

addons/api/addon/models/role.js

@@ -81,6 +81,32 @@ export default class RoleModel extends GeneratedRoleModel {
     return grantScopes;
   }
 
+  /**
+   * Helper for retrieving grant scope ids that are keywords.
+   * @type {string[]}
+   */
+  get grantScopeKeywords() {
+    return this.grant_scope_ids.filter((id) =>
+      GRANT_SCOPE_KEYWORDS.includes(id),
+    );
+  }
+
+  /**
+   * Helper for retrieving grant_scope_ids that are orgs.
+   * @type {string[]}
+   */
+  get grantScopeOrgIDs() {
+    return this.grant_scope_ids.filter((id) => id.startsWith('o_'));
+  }
+
+  /**
+   * Helper for retrieving grant_scope_ids that are projects.
+   * @type {string[]}
+   */
+  get grantScopeProjectIDs() {
+    return this.grant_scope_ids.filter((id) => id.startsWith('p_'));
+  }
+
   /**
    * A list of IDs for principals of type `user`.
    * @type {string[]}