Feature Request: Client Chooser Landing Page

[LexioJ]

As the ability to craft links to open locally installed apps exists (nextcloudtalk://), we are now missing some sort of web landing page as many other vendors provide today; see example screenshots:

… where the user is able to decide to join using their browser (aka web-experience) or dependent of the current connecting platform (talk clients exists for win/mac/linux/ios/android) to start the equivalent app by offering a dynamic crafted protocol handler url nextcloudtalk://open-conversation to start the locally installed app instead.

Talk on iOS for example does support the following parameters, some are given in the URL {server}/{withRoomToken} while others like {user} are known by the browser -> _last_logged_in_user:

server: The Nextcloud Server URL
user: Your UserID, used for an account on server, that is logged into the Talk App
withUser: The UserID of the user you want to talk to
withRoomToken: The room token of an existing room on server

Usage:
nextcloudtalk://open-conversation?server={serverURL}&user={userId}&withRoomToken={roomToken}

What do you think ?

Originally posted by @LexioJ in nextcloud/talk-ios#671 (comment)

[nickvergessen]

At the moment you can not join "any" server with the desktop client. So we would have to try and error if you don't have a profile on that server or are invited as a federated user.

But in general yes, we should try to improve this.

[SystemKeeper]

Also related to the iOS app: nextcloud/server#39069