Get staking on Versi

[eskimor]

In order to test Versi, we need validators staked on Versi. It should also be enabled on Rococo, but that is orthogonal.

Open tasks:

• [ ] Figure out how this is supposed to work with the validator-manager (talk with devops)
• [ ] Adjust chain spec for Versi to enable staking, based on Westend.
• [ ] Chainspec should also be usable for zombienet tests, so we can test slashing via zombienet as well.

[eskimor]

@tdimitrov can you take care of this one as well. I would be your buddy on this one, so we can do pairing sessions whenever that would seem useful.

[bkchr]

Why do you need staking? To test slashing?

[eskimor]

Zombienet tests are fine for now.