Enable representation of minefields according to MIL-STD 2525D

[harrywipperfuerth]

In ODIN minefields can be drawn statically as "one-point tactical graphic" symbols or

dynamically as a "Mined Area":

A representation of the object "Dynamic Depiction" occurs in an incorrect form as a "normal" area:

From a tactician's perspective, it would be worth discussing whether a representation of the "Mined Area" object analogous to MILSTD-2525D would be possible:

Examples:

[dehmer]

This would be really nice to have, but is probably not happening in the near future.
Moving to backlog.