Update Rotations.jl to 1.0

[rdeits]

• Quat -> UnitQuaternion
• RodriguesVec -> RotationVec
• SPQuat -> MRP (I'm not thrilled about that one. We can also introduce a type alias if you want).

Also add LightXML 0.9 compatibility (no changes as far as I can tell, except that it no longer needs BinaryProvider)

[rdeits]

Ah, ok, I think I'll need to regenerate the manifests on an older Julia version so they don't get the jll-specific dependencies. I also need to figure out why I'm getting an old version of MeshCatMechanisms--I think it might have a missing dependency upper bound on an old version.

[tkoolen]

Thanks. I went ahead and added a ModifiedRodriguesParam type alias; I agree that MRP is just a bad name. Updated example notebook manifests again. I'm also going to drop support for Julia < 1.3. I don't have the bandwidth to deal with all the various possible configurations stemming from the jll change, and e.g. DifferentialEquations has dropped support for < 1.3 as well. We have solid releases that work for earlier versions.