Spatial Harvesters [FABRIC]

 Fix block entities not being registered for energy capabilities in the Fabric version, the fix also removed some code redundancy.

This fix was submitted by TheVikingShip through the project's Discord as they were unable to submit a PR at the time. I forgot to add this credit to the commit message directly, probably because I was distracted by having been dealing with build issues for an hour. They gave me full copyright permission and ownership, which can be seen in both the Discord channel and the bridged Matrix room.