invite: Extend invite api for handling expiration duration.

This extends the invite api endpoints to handle an extra
argument, expiration duration, which states the number of
days before the invitation link expires.

For prereg users, expiration info is attached to event
object to pass it to invite queue processor in order to
create and send confirmation link.
In case of multiuse invites, confirmation links are
created directly inside do_create_multiuse_invite_link(),

For filtering valid user invites, expiration info stored in
Confirmation object is used, which is accessed by a prereg
user using reverse generic relations.

Fixes #16359.

zerver/views/invite.py

@@ -1,6 +1,7 @@
 import re
 from typing import List, Sequence, Set
 
+from django.conf import settings
 from django.http import HttpRequest, HttpResponse
 from django.utils.translation import gettext as _
 
@@ -35,6 +36,9 @@ def invite_users_backend(
     request: HttpRequest,
     user_profile: UserProfile,
     invitee_emails_raw: str = REQ("invitee_emails"),
+    invite_expires_in_days: int = REQ(
+        json_validator=check_int, default=settings.INVITATION_LINK_VALIDITY_DAYS
+    ),
     invite_as: int = REQ(json_validator=check_int, default=PreregistrationUser.INVITE_AS["MEMBER"]),
     stream_ids: List[int] = REQ(json_validator=check_list(check_int)),
 ) -> HttpResponse:
@@ -72,7 +76,7 @@ def invite_users_backend(
             )
         streams.append(stream)
 
-    do_invite_users(user_profile, invitee_emails, streams, invite_as)
+    do_invite_users(user_profile, invitee_emails, streams, invite_expires_in_days, invite_as)
     return json_success()
 
 
@@ -164,6 +168,9 @@ def resend_user_invite_email(
 def generate_multiuse_invite_backend(
     request: HttpRequest,
     user_profile: UserProfile,
+    invite_expires_in_days: int = REQ(
+        json_validator=check_int, default=settings.INVITATION_LINK_VALIDITY_DAYS
+    ),
     invite_as: int = REQ(json_validator=check_int, default=PreregistrationUser.INVITE_AS["MEMBER"]),
     stream_ids: Sequence[int] = REQ(json_validator=check_list(check_int), default=[]),
 ) -> HttpResponse:
@@ -177,5 +184,7 @@ def generate_multiuse_invite_backend(
             raise JsonableError(_("Invalid stream id {}. No invites were sent.").format(stream_id))
         streams.append(stream)
 
-    invite_link = do_create_multiuse_invite_link(user_profile, invite_as, streams)
+    invite_link = do_create_multiuse_invite_link(
+        user_profile, invite_as, invite_expires_in_days, streams
+    )
     return json_success({"invite_link": invite_link})