Adapt https://github.com/aya-rs/aya/commit/3d463a3 and subsequent work
to the template. This has worked very well for us in the main project,
and our users should get the same hotness.
Note that xtask is still used for running, as it is in the main project.
User may specify a program_type by prompt or CLI flag.
We then generate skeleton code to the ebpf program for a noop program of
that type.
Requires cargo-generate@main
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>