Get suspended status from the active baker

[td202]

Purpose

Closes: #1309
Depends on: Concordium/concordium-grpc-api#76 Concordium/concordium-base#590

Changes

• Derive suspended status (in doGetPoolStatus) from the active baker status.

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.