Add Zombienet integration test and bootstrap a demo community

[clangenb]

WIP, some weird errors:

• Sometimes there is tx-status invalid. I can't understand why
• bootstrap test has wrong balance at the end of the test for bob (solonode passes). Is the runtime too old?

[clangenb]

I think I found the cause for both issues:

• invalid tx: alice nonce collision with fauce -> solution make bob councillor and use bob to set up the community like in the solonode
• wrong balance bob, increase tx fees on the parachain.