fix(auth): allow password managers to pre-fill input fields (#9390)

HTML disallows having multiple IDs with the same value.

In reality this is for 1Password's feature where you can create
custom fields named like input IDs and 1Password fill pre-fill that.

test/e2e-cypress/e2e/features/oauth2-flows/password.cy.js

@@ -18,11 +18,11 @@ describe("OAuth2 Password flow", function() {
       .get("#password_type")
       .select("basic")
 
-      .get("#client_id")
+      .get("#client_id_password")
       .clear()
       .type("application")
 
-      .get("#client_secret")
+      .get("#client_secret_password")
       .clear()
       .type("secret")
 
@@ -75,11 +75,11 @@ describe("OAuth2 Password flow", function() {
       .get("#password_type")
       .select("request-body")
 
-      .get("#client_id")
+      .get("#client_id_password")
       .clear()
       .type("application")
 
-      .get("#client_secret")
+      .get("#client_secret_password")
       .clear()
       .type("secret")