Add support for the Personal Ownership policy

Upstream refs:

* https://github.com/bitwarden/server/pull/1013
* https://bitwarden.com/help/article/policies/#personal-ownership

src/api/core/organizations.rs

@@ -966,7 +966,7 @@ fn list_policies_token(org_id: String, token: String, conn: DbConn) -> JsonResul
 fn get_policy(org_id: String, pol_type: i32, _headers: AdminHeaders, conn: DbConn) -> JsonResult {
     let pol_type_enum = match OrgPolicyType::from_i32(pol_type) {
         Some(pt) => pt,
-        None => err!("Invalid policy type"),
+        None => err!("Invalid or unsupported policy type"),
     };
 
     let policy = match OrgPolicy::find_by_org_and_type(&org_id, pol_type, &conn) {
@@ -1056,4 +1056,4 @@ fn get_plans(_headers: Headers, _conn: DbConn) -> JsonResult {
         ],
         "ContinuationToken": null
     })))
-}
+}