## Why this should be merged
Required for SAE to support more of the required APIs. I left out the
account and personal APIs, as we really shouldn't be managing any keys
on the node.
## How this works
Follows the same style that already existed. Additionally, copied the
upstream description for the types.
## How this was tested
Only local testing (although the prior functions were also not tested)
## Why this should be merged
Exposes API implementations for use by SAE.
## How this works
Type aliases and constructor propagation.
## How this was tested
N/A
