Implement the presence module

[babolivier]

• Implement the m.presence event
• Implement PUT /_matrix/client/r0/presence/{userId}/status
• Implement GET /_matrix/client/r0/presence/{userId}/status
• Implement POST /_matrix/client/r0/presence/list/{userId}
• Implement GET /_matrix/client/r0/presence/list/{userId}
• Implement setting and getting presence through /sync

[kegsay]

Related sytests:

    × GET /presence/:user_id/status fetches initial status
    × PUT /presence/:user_id/status updates my presence
    × Presence change reports an event to myself
    × Friends presence changes reports events
    × Presence changes are reported to local room members
    × Presence changes are also reported to remote room members
    × Presence changes to UNAVAILABLE are reported to local room members
    × Presence changes to UNAVAILABLE are reported to remote room members
    × New federated private chats get full presence information (SYN-115)
    × Left room members do not cause problems for presence
    Sync API:
    × Existing members see new member's presence
    × Get presence for newly joined members in incremental sync
    × User sees their own presence in a sync
    × User sees updates to presence from other users in the incremental sync.

[alexkursell]

I would love to take a crack at implementing this! I assume that the implementation would be somewhat similar to #1528.

[ptman]

Assuming this is the resource sink it is for synapse, there should be a toggle for turning presence off.

[S7evinK]

I would love to take a crack at implementing this! I assume that the implementation would be somewhat similar to #1528.

@alexkursell: Are you still on it or need help? Should be pretty similar to #1528.

[neilalexander]

This landed in Dendrite 0.8.0.