feat: add upstream substrait version to package

[gforsyth]

There's the version of substrait the Python package and the version of substrait the spec / proto implementation.

Maybe we can add __substrait_version__ and have that refer to the version of the submodule?

[gforsyth]

This is actually necessary, I realize, because the upstream version needs to be inserted into a Substrait plan.

[westonpace]

It might also be nice to have __minimum_substrait_version__ and it should probably be enforced (e.g. reject a plan if the version is too small) which is the minimum version of a substrait plan that you will import. This can be equal to __substrait_version__ initially but protobuf is pretty robust with backwards compatibility so it should be possible to be easy to support older versions (to an extent).