Improve auto utils

[marc-aurele-besner]

Improve auto utils

My thoughts were adding more functions and types exported by auto-utils: to look at what Astral uses from polkadot packages and try to expose these same functions and types in our SDK.

• Add function to decode the public address from the regular address #56
• Add function to sign and verify message #57
• Add function to generate seed, expose keyring and more utility #58
• Deconstruct some flow (like register operator) to expose internal helper function (like createType) #59
• Export more types #60

[jfrank-summit]

I was hoping you would do this!