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/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>