Include MVDS deployment in spec

[oskarth]

Considering we are going to use MVDS for v1 1:1 chats (https://github.com/status-im/bigbrother-specs/blob/master/data_sync/mvds.md), this should be reflected in the current specifications.

It is OK if we reference the MVDS spec and let it live elsewhere, but it has to be mentioned at least within some scope.

@decanus @cammellos

[oskarth]

Currently the only mention of MVDS in specs we have is here

Status payloads are serialized and then wrapped inside a MVDS message which is added to an MVDS payload, this payload is then encrypted (if necessary for 1-to-1 / group-chats) and sent using whisper which also encrypts it.

Are we happy with this? If not, what changes do we want to make for this?
cc @corpetty @adambabik @cammellos @decanus

[decanus]

@oskarth, we should also mention which version of MVDS we use.

[cammellos]

We should describe how we use groups probably, currently we just use pk1-pk2 where pks are ordered ASC , but we might want to rethink this (does not take into consideration multiple devices, which works fine, but maybe there's better)

[oskarth]

Ping @decanus could you add this?

Also, are we using https://specs.vac.dev/specs/mvds-metadata.html in v1? @cammellos

[cammellos]

We don't use metadata in the app

[decanus]

@oskarth, which part would you like me to add? the groups? I think @cammellos may have more in detail knowledge on this than I do.