keymgr: Replace EncodableKey::to_bytes() with SSH-specific function.
The EncodableKey::to_bytes
function didn't make much sense, because
not all keys have a canonical byte representation.
This commit replaces EncodableKey::to_bytes
with
EncodableKey::as_ssh_keypair_data
. In the future, EncodableKey
will
grow functions for encoding keys in other storage formats too.
Supersedes !1437 (closed)
Closes #965 (closed)
Edited by gabi-250