fix: everest_api/evse_manager/cmd/force_unlock to also stop any transaction

[james-ctc]

Describe your changes

everest_api/evse_manager/cmd/force_unlock didn't previously stop any transactions first. OCPP UnlockConnector did stop transaction first and then unlock connector.

This update means that everest_api/evse_manager/cmd/force_unlock does the same as OCPP UnlockConnector

Issue ticket number and link

Checklist before requesting a review

• [X] I have performed a self-review of my code
• [ ] I have made corresponding changes to the documentation
• [ ] I read the contribution documentation and made sure that my changes meet its requirements