Add support for the improved Invite Links (#639)

* Add new invite link export methods

* Implement higher-level Invite type

* Update Docstrings and rename Invite

* Docstrings are now more consistent with other methods
* Invite is now InviteLink to be less arbitrary

* Add method to get exported links

* `get_exported_chat_invites`
* prepare `__init__` for the other InvitesV2 methods

* Update returned type

`str` -> `types.InviteLink`

* Add method to edit invite link

Since editing the link returns a slightly different type to exporting,
I have made a small "hack" in the InviteLink type.

* Move Invites V2 methods to their own namespace

* Add get_chat_invite_importers and InviteImporter

Method to fetch information on users that joined via a specific link and
the type to display the information

* Add methods to delete revoked links

* delete_exported_chat_invite to delete a single revoked link
* delete_revoked_exported_chat_invites to delete all revoked links of a
specified admin

* Renaming Invite(s) to InviteLink(s)

As per @delivrance's request
https://github.com/pyrogram/pyrogram/pull/630#issuecomment-791893890

Also sorted invites' __init__ alphabetically

* Add Method to get admins with exported invite link

Documentation needs an update and the respective type needs to be
created. I cannot test this, as I lack Creator permissions.

* Invite Links overhaul

* Rearrange code

Co-authored-by: Dan <14043624+delivrance@users.noreply.github.com>

compiler/docs/template/methods.rst

@@ -88,6 +88,19 @@ Users
 
     {users}
 
+Invite Links
+------------
+
+.. autosummary::
+    :nosignatures:
+
+    {invite_links}
+
+.. toctree::
+    :hidden:
+
+    {invite_links}
+
 Contacts
 --------