Separate Stake and Stake Pool keys

[LGLO]

Description

Separates StakePoolPublicKey and StakePublicKey and their respective signatures into separate types.
Before there was just MainchainPublicKey, but I argue that Stake key and StakePool key are two different things in the domain, used for different activities.

Please let me know what you think

This PR doesn't separate their hashes, it still is MainchainKeyHash.

Checklist

• Commit sequence broadly makes sense and commits have useful messages.
• New tests are added if needed and existing tests are updated.
• Relevant logging and metrics added
• CI passes. See note on CI.
• Any changes are noted in the changelog.md for affected crate
• Self-reviewed the diff

[AmbientTea]

splendid

[kpinter-iohk]

I really like this change. In some places the variable names were not updated to match the new type, I marked these with suggestions. I got into it and by the time I realized how spammy this could be on GH I was nearly done already, sorry about that. If you prefer I could make these fixes myself and push on your branch.

[LGLO]

I really like this change. In some places the variable names were not updated to match the new type, I marked these with suggestions. I got into it and by the time I realized how spammy this could be on GH I was nearly done already, sorry about that. If you prefer I could make these fixes myself and push on your branch.

I haven't mostly changed variables names. Perhaps some could be changed, but I am not going to break any existing interface that has been released (v1.5.0 or earlier) for sake of matching them. No CLI params changes. No JSON fields name changes. No extrinsic calls changes.

[kpinter-iohk]

No CLI params changes

Not even with an alias, preserving compatibility, like I suggested?

[kpinter-iohk]

🎉