Make Movement available on PyPI

[joewallwork]

It would be amazing to get support for

python3 firedrake-install --install movement

[joewallwork]

Probably best to upstream gradient and Hessian recovery first, as discussed in #122.

[ddundo]

@jwallwork23 with the new firedrake installation process, firedrake-install is no longer recommended and it raises a FutureWarning (see https://github.com/firedrakeproject/firedrake/blob/09cb050929f6aaa9a3bc71ec7e4b0aae9bca854a/scripts/firedrake-install#L23-L28 ). Now firedrake and other packages should be installed via pip.

So perhaps this could be closed?

[joewallwork]

Thanks for pointing this out. I instead renamed the issue because the equivalent thing to do now would be to get Movement installable on PyPI.