expose "ax" and "dims" arguments to animate(...), to be consistent with other API's;
update animate implementation to be consistent with trajectory frame's data type, in particular, SE3Array / SO3Array types instead of SE3 / SO3, in line with animate.run(...)'s implementation.
Example use-cases:
...
ax = fig.add_subplot(111, projection='3d')
T1.plot(ax=ax, dims=[-5, 10])
T1.animate(start=T2, ax=ax) # would use the existing ax which is [-5, 10]
# T1.animate(start=T2, ax=ax, dims=[-10, 10]) # would use the existing ax and override its lims to [-10, 10]
plt.show()
Fix several issues related to #126
Example use-cases: