feat: 🎸 Populate subject for OIDC account name displays (#2757)

OIDC accounts are guaranteed to have a subject claim which we should
display. Currently we only look at email and full_name which
are all optional for OIDC claims. Also added deep links for accounts.

✅ Closes: https://hashicorp.atlassian.net/browse/ICU-16634

addons/api/addon/models/account.js

@@ -47,8 +47,8 @@ export default class AccountModel extends GeneratedAccountModel {
    * @type {string}
    */
   get accountName() {
-    const { email, full_name, login_name } = this;
-    return email || full_name || login_name;
+    const { email, full_name, login_name, subject } = this;
+    return email || full_name || login_name || subject;
   }
 
   // =methods