Add raw RPC calls

[smiasojed]

Summary

Closes #987

• y/n | Does it introduce breaking changes?
• y/n | Is it dependent on the specific version of ink or pallet-contracts?

Add raw RPC calls

Description

Invoke an RPC call to the node in the format:
cargo contract rpc [Options] METHOD [PARAMS]

e.g.

cargo contract rpc author_insertKey '"sr25"' '"//ALICE"' \
      5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY

Checklist before requesting a review

• My code follows the style guidelines of this project
• I have added an entry to CHANGELOG.md
• I have commented my code, particularly in hard-to-understand areas
• I have added tests that prove my fix is effective or that my feature works
• Any dependent changes have been merged and published in downstream modules

[SkymanOne]

Is there a way to automatically convert it to string to make it consistent? I see this as a source of user errors in future.

[smiasojed]

Is there a way to automatically convert it to string to make it consistent? I see this as a source of user errors in future.

You would need to know for which command it is required. In this case, it means hardcoding the command name and matching agains it.

One idea could be to create metadata for RPC methods and, based on this, convert the input. However, we are currently in a transition period between legacy RPC and the new implementation, which is not finished yet. Therefore, I decided not to create the metadata now.

[SkymanOne]

Sure, then I would create an issue for this, so we can pick it up later

[SkymanOne]

LGTM, just few nits