Adds a system for refitting species clothing
Fixes modkits

Fixes modkits not tracking suit/helmet parts, not checking allowed
parts, and not checking if the clothing needs to be modified.
Updates eng rig path, adds obj sprites

Adds object sprite sheets for tajaran, unathi and skrell hardsuits, where the icons were available (just engineering and syndie hardsuits for now).

Makes engineering hardsuits a subtype of the parent rig type, so it is
now possible to update eng hardsuits without affecting every other
hardsuit type.
Fixes skrell helmet refitting, modkit text
Merge pull request #5704 from mwerezak/species-refit

Fixes object icons not being updated when refitting hardsuits for different species