Make handler types generic

[stwiname]

Description

Update Substrate extrinsic and event types to be generic. This allows users to specify the arguments of a transaction, the follow up to this would be codegen that builds a type based on these generic parameters

Example:

// Event
async function handleEvmLog(event: SubstrateEvent<[EvmLog]>): Promise<void> {

  // `eventData` will be of type `EvmLog` before it would have been `Codec`
  const [eventData] = original.event.data; 
}

// Call 
async function handleEvmCall(call: SubstrateExtrinsic<[TransactionV2 | EthTransaction]>): Promise<void> {

  // `tx` will be of type `TransactionV2 | EthTransaction` before it would have been `Codec`
  const [tx] = original.extrinsic.method.args;
}

Completes step 1 of #1139

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist

• I have tested locally
• I have performed a self review of my changes
• Updated any relevant documentation Document substrate extrinsic and event generics documentation#201
• Linked to any relevant issues
• I have added tests relevant to my changes
• Any dependent changes have been merged and published in downstream modules
• My code is up to date with the base branch