Bugfix - connecting worker with waiting job crashes worker

Description

Fixes the bug where connecting a worker when there is a job waiting to be claimed crashes the worker. Closes #179 (closed)

Changes

The worker pool now maintains a list of unencryptedWorkers, where workers are kept until they receive the 'bob' control message. After this, they are moved to the idle list.

Additions

N/A

Test and Review

To be filled in by the reviewers

• All of the methods are commented to expectation

• The methods are tested to satisfaction

• There are no unnecessary files present in the MR

• The continuous integration has no problems with the MR

• The MR is filled in as requested (including labels, milestones, and reviewers)

• The documentation is up-to-date

• All nullable parameters are marked as such