Parity Signer support

[Slesarew]

To become compatible with Parity Signer now, Centrifuge should either:

a. Update metadata version to at least v12 AND add all missing types to Signer's legacy types definitions file

OR

b. Update metadata version to at least v14

After that, as a convenience for users, signed network addition and metadata updates might be hosted somewhere. Either contact maintainers of Parity metadata portal to use their certificate or issue your own; preferably both. Certificates are temporary measure until chains are made to check metadata validity in trustless way.

All this is needed for offline transaction parsing and display. I'm leaving this ticket here because Signer's users asked about support in Signer's repo novasamatech/parity-signer#927.

[mustermeiszer]

@Slesarew We will phase out the current stand-alone chain of Centrifuge in favor of the Parachain that will be onboarded to polkadot. The parachain will of course support latest metadata. I am closing this therefore. If there are any questions left or my answer doesn`t solve the problem, feel free to comment again.

Edit:
Removed date of onboarding as I am not sure when exactly polkadot onboard the second batch of parachains.