Fix commission sort and baker mentions

[ghost]

Purpose

Validator commission sort was broken after changing commissions shown to be new current payday value. Also some mentions of baker was not mapped to delegators.

https://concordium.atlassian.net/browse/CBW-1484

Changes

• Change from baker to validator
• Fix sort

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.