added service account header removed duplicate sign in button

locales/cy/common.json

@@ -38,6 +38,7 @@
   "footer-guidance-link": "https://llyw.cymru/penderfyndiadau-cynllunio-ac-amgylchedd-cymru/canllawiau-gwasanaethau",
   "mobile-nav-label": "Dewislen",
   "signout-label": "Allgofnodwch",
+  "signin-label": "Mewngofnodwch",
   "back-to-top-link": "Nôl i dop y dudalen",
   "social-bar-share-link": "Rhannu’r dudalen hon",
   "social-bar-share-via-link": "Rhannu’r dudalen hon ar",

locales/en/common.json

@@ -38,6 +38,7 @@
   "footer-guidance-link": "https://gov.wales/planning-and-environment-decisions-wales/guidance-services",
   "mobile-nav-label": "Menu",
   "signout-label": "Sign out",
+  "signin-label": "Sign in",
   "back-to-top-link": "Back to top",
   "social-bar-share-link": "Share this page",
   "social-bar-share-via-link": "Share this page via",