First step into elastic scaling: Having a para be on multiple cores,
will not get it more throughput yet, but it will no longer brick it.

This is a backport PR, as this would benefit the Coretime launch on
Kusama.

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Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
Signed-off-by: alindima <alin@parity.io>
Co-authored-by: Andrei Sandu <54316454+sandreim@users.noreply.github.com>
Co-authored-by: alindima <alin@parity.io>
Co-authored-by: eskimor <eskimor@no-such-url.com>