Add granularity to planets

[GalacticChimp]

Split planets into components/elements/something, to allow stuff placing buildings, armies having a concrete position on the planet etc.

One way of doing this is use a simple grid cell system.

[felipeStouvenel]

Grid system is on the works. Will probably do a PR once im satisfied with the grid generation and tile information system. Then will do the drawing of it for the Monastery world. If all goes well will have a robust system to spawn and have as much information about each individual tile as possible (which in turn will help with the ground combat rework)

[felipeStouvenel]

Created #174 for the first iteration of this