Add the functionality the the pipeline infrastructure and CLI to run
individual pipe and analyses as subcommands instead of in-process. This
allow better debuggability of individual pipes.
In preparation for debugging individual pipes add an additional method
to the `Pipe` interface, `needed_files`, which allows the pipe to
statically report which files it will request ahead of time.
Improve the handling of signals by leveraging the `Py_AtExit`
functionality to trigger cleanup when the interpreter exits.
When receiving SIGINT handle it specially because exceptions in python
are only thrown when the interpreter is running and not when C code is.
Introduce the `ImportFiles` pipe which leverages the newly-introduced
`FileStorage` to fetch the required files and store them in the
`BinariesContainer`.
Add the needed infrastructures that allow ephemeral classes (`PipeRun`s)
to be wrapped as a regular pypeline `Pipe` class. These automatically
have their dependencies tracked and propagated to the pypeline.
Alessandro Di Federico