streaming-data-types: one repo for schemas and bindings

[rerpha]

To avoid bindings going out of sync with the schema repository, it would be good if we had one repository which automatically (on CI) builds bindings and publishes them to pypi/crates.io for python and rust respectively.

[Tom-Willemsen]

This was completed in ISISComputingGroup/streaming-data-types#4

We now have a "source of truth" repo with both Python & rust bindings being published (and if we want other languages in future, that is also possible).