Crypto | There is no way to tell the difference between a clear to device and a decrypted to device

[BillCarsonFr]

receive_sync_changes takes the to_device events from the sync and return a "decrypted version" of them.

So an app using the crypto sdk have no way to make the difference from a to device sent in clear vs a to device succesfully decrypted.

In comparison room events (megolm) when decrypted give information regarding the decryption (EncryptionInfo)

https://github.com/matrix-org/matrix-rust-sdk/blob/9f7179263a4c7775d253a29b13477f43f15b9293/crates/matrix-sdk-crypto/src/machine/mod.rs#L1260-L1268