Remove duplicate message definition

[jarkenau]

The point and vector3 have the same message definition. We should merge them into one for pb and fb. Same for the stamped variants.

seerep/seerep-msgs/fbs/point.fbs

Lines 2 to 8 in 1d1a7ca

	namespace seerep.fb;
	table Point {
	x:double;
	y:double;
	z:double;
	}

seerep/seerep-msgs/fbs/vector3.fbs

Lines 2 to 8 in 1d1a7ca

	namespace seerep.fb;
	table Vector3 {
	x:double;
	y:double;
	z:double;
	}