Line Start and End Move Along Path?

[NateAGeek]

Description of proposed feature

Currently is seems we have MoveAlongPath. However, I'm not sure if there is an ability to move a lines start and end on a path. I'd like to maybe make it so we can have a vector tip follow a path, however, that would require some minor rework of this code.

class MoveEndAlongPath(Animation):
    def __init__(
        self,
        mobject: "Vector",
        path: np.ndarray,
        suspend_mobject_updating: Optional[bool] = False,
        **kwargs
    ) -> None:
        self.path = path
        super().__init__(
            mobject, suspend_mobject_updating=suspend_mobject_updating, **kwargs
        )

    def interpolate_mobject(self, alpha: float) -> None:
        point = self.path.point_from_proportion(self.rate_func(alpha))
        self.mobject.set_points_by_ends(start=self.mobject.get_start(), end=point)

class MoveStartAlongPath(Animation):
    def __init__(
        self,
        mobject: "Vector",
        path: np.ndarray,
        suspend_mobject_updating: Optional[bool] = False,
        **kwargs
    ) -> None:
        self.path = path
        super().__init__(
            mobject, suspend_mobject_updating=suspend_mobject_updating, **kwargs
        )

    def interpolate_mobject(self, alpha: float) -> None:
        point = self.path.point_from_proportion(self.rate_func(alpha))
        self.mobject.set_points_by_ends(start=point, end=self.mobject.get_end())

How can the new feature be used?

I think it could be useful, specifically with vectors, to draw them along a path.