Migrate action, common, a11y translation keys

```
move () {
  FROM=$1 TO=$2 find public/locales -type f -exec sh -c 'jq ".$TO = .\"$FROM\" | del(.\"$FROM\") | del(..|nulls) | select(length > 0)" {} | sponge {}' \;
}

move "Avatar" "common.avatar"
move "Camera" "common.camera"
move "Close" "action.close"
move "Copied!" "common.copied"
move "Copy" "action.copy"
move "Copy link" "action.copy_link"
move "Encrypted" "common.encrypted"
move "Go" "action.go"
move "Home" "common.home"
move "Invite" "action.invite"
move "Loading…" "common.loading"
move "Microphone" "common.microphone"
move "No" "action.no"
move "Not encrypted" "common.unencrypted"
move "Password" "common.password"
move "Profile" "common.profile"
move "Username" "common.username"
move "Video" "common.video"
move "Register" "action.register"
move "Remove" "action.remove"
move "Settings" "common.settings"
move "Sign in" "action.sign_in"
move "Sign out" "action.sign_out"
move "Submit" "action.submit"
move "User menu" "a11y.user_menu"
move "Audio" "common.audio"
move "Display name" "common.display_name"
```

src/room/CallEndedView.tsx

@@ -140,7 +140,7 @@ export const CallEndedView: FC<Props> = ({
               variant="default"
               data-testid="home_go"
             >
-              {submitting ? t("Submitting…") : t("Submit")}
+              {submitting ? t("Submitting…") : ("action.submit")}
             </Button>
           )}
         </FieldRow>

src/room/EncryptionLock.tsx

@@ -32,7 +32,7 @@ export const EncryptionLock: FC<Props> = ({ encrypted }) => {
 
   return (
     <Tooltip
-      label={encrypted ? t("Encrypted") : t("Not encrypted")}
+      label={encrypted ? t("common.encrypted") : t("common.unencrypted")}
       side="right"
     >
       <Icon

src/room/GroupCallLoader.tsx

@@ -54,7 +54,7 @@ export function GroupCallLoader({
     case "loading":
       return (
         <FullScreenView>
-          <h1>{t("Loading…")}</h1>
+          <h1>{t("common.loading")}</h1>
         </FullScreenView>
       );
     case "loaded":
@@ -72,7 +72,7 @@ export function GroupCallLoader({
             {/* XXX: A 'create it for me' button would be the obvious UX here. Two screens already have
             dupes of this flow, let's make a common component and put it here. */}
             <Link href="/" onClick={onHomeClick}>
-              {t("Home")}
+              {t("common.home")}
             </Link>
           </FullScreenView>
         );

src/room/GroupCallView.tsx

@@ -309,7 +309,7 @@ export const GroupCallView: FC<Props> = ({
           )}
         </Text>
         <Link href="/" onClick={onHomeClick}>
-          {t("Home")}
+          {t("common.home")}
         </Link>
       </FullScreenView>
     );

src/room/InviteModal.tsx

@@ -68,7 +68,7 @@ export const InviteModal: FC<Props> = ({ room, open, onDismiss }) => {
           onClick={onButtonClick}
           data-testid="modal_inviteLink"
         >
-          {t("Copy link")}
+          {t("action.copy_link")}
         </Button>
       </Modal>
       <Toast

src/room/RoomAuthView.tsx

@@ -76,8 +76,8 @@ export const RoomAuthView: FC = () => {
               <InputField
                 id="displayName"
                 name="displayName"
-                label={t("Display name")}
-                placeholder={t("Display name")}
+                label={t("common.display_name")}
+                placeholder={t("common.display_name")}
                 data-testid="joincall_displayName"
                 type="text"
                 required
@@ -103,7 +103,7 @@ export const RoomAuthView: FC = () => {
               disabled={loading}
               data-testid="joincall_joincall"
             >
-              {loading ? t("Loading…") : t("Join call now")}
+              {loading ? t("common.loading") : t("Join call now")}
             </Button>
             <div id={recaptchaId} />
           </Form>