Fixes missing icons for xenoarchaeology items EXCEPT for the energy guns.
Fixes the xenoarch eguns.

This was done by making the xenoarch eguns new subtypes with different update_icon() procs than the regular eguns. The new subtypes are in finds_eguns.dm
Fixes a bug where core samplers dispensed bags that you could not take rock slivers out of.
Merge pull request #7077 from MagmaRam/bugfix

Fixes xenoarch find sprites and core samplers not working