[FEATURE] Validation

[Firestone82]

Request for implementation of part validation algoritms that will do the following.
Source at: ValidationController.java

Validate:

1. Part must have at least 5 hexes
2. Part must have at most 50 hexes
3. Part is maximum 8 hexes wide and 8 hexes tall
4. All hexes must be connected

[Kkobarii]

Must the part include the starting hex (0,0,0)? It would make the connection validation more streamlined.

[Kkobarii]

Hexes can't overlap.

[Kkobarii]

Continuing, the validation documentation will be available here (with output docs here). Add anything I should do, just ping me please.