ElementR: mark everything in js-sdk that is no longer supported as deprecated

[richvdh]

There are quite a lot of methods in MatrixClient that will not work correctly with Element-R, and which have been replaced, but have yet to be marked as deprecated. Examples:

• isEventSenderVerified
• getEventSenderDeviceInfo
• getOutgoingRoomKeyRequest
• requestSecret

We should audit for places that use MatrixClient.crypto, and either deprecate them, or plan to fix them.

[BillCarsonFr]

There is this also sendSharedHistoryKeys

[BillCarsonFr]

Quick not on requestSecret there is an API (since 3.5.0) on rust that allows to requestMissingSecrets. It's not an exact mapping but there might be a way to replace it.

[BillCarsonFr]

Looks like there is a slash command called remakeolm that was available in legacy crypto. No effect in rust

https://github.com/matrix-org/matrix-react-sdk/blob/618462ba06d1d2f64fc589402198529dceae8fe2/src/SlashCommands.tsx#L761