Add matrix share

[Sorunome]

As discussed, this adds the matrix share thing and renames some of the existing things to be element-specific, so that it can be a general matrix integration

As soru isn't too sure how to do all that vue stuff, she dropped her files into the js-old folder, so that you have a general idea what is going on.

None of this is tested atm in this repo, hence the draft state ^^"

[gary-kim]

Something to watch out for is that a lot of Nextcloud instances do not have pretty URLs enabled so their Matrix paths would look like https://cloud.example.com/index.php/_matrix/....

Also, for the root path things, we can see if this app can also be added to the list of root allowed apps. Just need to be added here: https://github.com/nextcloud/server/blob/17e58f5056f9a0ef1620e6611091a2302fbfed14/lib/private/AppFramework/Routing/RouteConfig.php#L56-L63

[Sorunome]

For it to work with federation you have to either set up .well-known or an srv record or have nextcloud listen to port 8448, too, so it needs more extra setup.

Setups with prefix / suffix being non-blank and a domain other than that of nextcloud are, of course, more complicated.

[Thatoo]

If one makes the change in lib/private/AppFramework/Routing/RouteConfig.php to add 'riotchat' to the list of rootUrlApps, would it be possible to test a version of riotchat on Nextcloud that have this sharing feature?

[Thatoo]

Also, would it be possible to make an MSC to move forward?
I'm understood that it has something to do with .well-known to Indicate subpaths for media repository in .well-known.
But I'm not sure to know which .well-know, server or client?
Am I right thinking it is linked to this discussion matrix-org/matrix-spec#693 ?
I'm not sure because of what uhoreg is saying.

[Thatoo]

😢

[Sorunome]

soru is not committed to merging this stuffs anymore, sorry