Issue with excavators

Issue description

Excavators have the ability to climb terrain that trucks can not. This creates a host problems, as the current pathing will often lead exacavtors to areas where trucks can not rech or they will mine themselves into a hole where no truck can reach them.

Please set a rule that excavators will not pass through or pass next to a mineable tile when moving. but will instead stop at it and mine it. Or make it so both them and trucks have the exact same mobility.

Also please set the tuck logic so that they will follow their assigned excavator untill they are full. Currently they will return to the mining tower if the excavator moves and something breaks their assignation despite there being plenty of tiles to mine (likely excavator moving to area where trucks can not follow.

Reproduction steps

This issue is dependant on the mine layout: entrance location, tower location, etc.
Save file: https://gofile.io/d/ycjmac

Game version and build number

v0.7.8a b486

Operating system

Windows

Update: Specifically tiles which are not inaccessible on all four sies (red sides). Excavators should not be able to mine any tiles that have no access to a legitimate path. Coupled with the removal of the ability to go into areas where no truck can follow, this should go a long way to stop excavators and theire trucks getting stuck.