Add CLI and library for extrinsics interaction

[jmg-duarte]

Description

Fixes #130

I've ended up introducing a separate CLI as I thought it would be weird to join two very separate sides in a single binary. If the team disagrees, I can put it in a single place.

The binary itself should be discoverable as is, but just --helping your way through.
Testing with the scenarios for the integration tests would be great to ensure this is working.

I'm looking for feedback and questions!

Important points for reviewers

subxt is a weird beast, take a look into the docs while reading the PR.

Keep in mind that some types needed wrappers or similar because of conversions to bounded vecs and friends.

Checklist

• Are there important points that reviewers should know?
• Make sure that you described what this change does.
• If there are follow-ups, have you created issues for them?
  • Storagext: Add Storage Provider pallet #151
• Have you tested this solution?
• Were there any alternative implementations considered?
• Did you document new (or modified) APIs?

[th7nder]

you did a lot of evil magic! great work, let's iron out some intricacies and roll with it

I didn't run the code yet, will do that tomorrow -> wanna publish the findings of just reading the code for now.

[cernicc]

Wow. Good job figuring out the subxt 💪

• I have a feeeling that at the end we might have a single cli endpoint for both provider and client. The polka-storage-provider might only be used for configuring and starting up the provider server and that is it.

• Run taplo fmt before taging the pr. It will fail currently.

• Do you have an idea how should we version the motadata.scale?

[jmg-duarte]

I have a feeeling that at the end we might have a single cli endpoint for both provider and client. The polka-storage-provider might only be used for configuring and starting up the provider server and that is it.

We might, but the library at least was necessary and the current CLI is very cluttered already. Joining them later isn't too hard.

Do you have an idea how should we version the motadata.scale?

Honestly, no. We can just keep incrementing the name once someone makes a change, but since it's a binary blob it's really hard. The alternative is to codegen everything and check that in.

[th7nder]

TREMENDOUSLY HUGE GREAT WORK!

[cernicc]

Nice 💪 Great job!