Rename PrimitiveType to DdlPrimitiveDataType
Rename PrimitiveType to DdlPrimitiveDataType

For naming consistency and conformance with calling `string`, `int16` ...
data types in the openddl/opengex specification.

Signed-off-by: Squareys <0f6a03d4883e012ba4cb2c581a68f35544703cd6@googlemail.com>

Squareys/PyDDL