fix(participants-pane) enable translation of invite button

Copy over existing "invite" translations where the participants
pane is already translated.

Signed-off-by: Christoph Settgast <csett86@web.de>

lang/main-it.json

             "participantsList": "({{count}}) partecipanti"
         },
         "actions": {
+            "invite": "Invita persone",
             "muteAll": "Silenzia tutti",
             "stopVideo": "Ferma il video"
         }

lang/main-te.json

             "participantsList": "సదస్యులు ({{count}})"
         },
         "actions": {
+            "invite": "ప్రజలను ఆహ్వానించు",
             "muteAll": "అందరినీ మౌనించు",
             "stopVideo": "వీడియో ఆపివేయి"
         }

lang/main.json

             "participantsList": "Meeting participants ({{count}})"
         },
         "actions": {
+            "invite": "Invite Someone",
             "muteAll": "Mute all",
             "stopVideo": "Stop video"
         }

react/features/participants-pane/components/InviteButton.js

             <Icon
                 size = { 20 }
                 src = { IconInviteMore } />
-            <span>Invite Someone</span>
+            <span>{t('participantsPane.actions.invite')}</span>
         </ParticipantInviteButton>
     );
 };