Validator score chain parameters

[drsk0]

Purpose

Add validator score parameters to chain parameters. The grpc changes need to go in first (Concordium/concordium-grpc-api#66)

Changes

This adds new parameters for validator suspension and all the necessary boilerplate code.

Checklist

• My code follows the style of this project.
• The code compiles without warnings.
• I have performed a self-review of the changes.
• I have documented my code, in particular the intent of the
  hard-to-understand areas.
• (If necessary) I have updated the CHANGELOG.

CLA acceptance

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• link: https://developers.concordium.com/CLAs/Contributor-License-Agreement-v1.0.pdf

• I accept the above linked CLA.

[td202]

This approach seems fine. I think the GRPC interface will need to be updated to.

[td202]

I think we also need to define an UpdatePayload constructor (in Updates.hs) for updating the new chain parameter.

[drsk0]

@td202 I added the new update type to Update.hs. The grpc api also needs to be extended: Concordium/concordium-grpc-api#71.

[td202]

Looks good. Main thing missing is the handling of the new update payload in GRPC2.hs.

[td202]

Looks good! Thanks