feat(cast): add event-decode command to parsing and formatting log data

[mitchmindtree]

Component

Cast

Describe the feature you would like

With cast, we can fetch the logs with:

cast logs

We can filter down to the events that we care about by providing a signature:

cast logs "MyEvent(uint256 foo, uint256 bar)"

However the stdout still gives us unformatted, raw data (despite knowing the Event signature):

...
data: 0x000000000000000000000000000000000000000000000000000000000000004d000000000000000000000000000000000000000000000000000000000000004d
...

This makes sense for ensuring cast logs has consistent behaviour. That said it would be nice if there was a way that cast could use the signature to output the fields in a formatted manner. E.g. something like:

cast decode-event --json "MyEvent(uint256 foo, uint256 bar)" 0x000000000000000000000000000000000000000000000000000000000000004d000000000000000000000000000000000000000000000000000000000000004d

Which outputs something like:

{
    "foo": "0x000000000000000000000000000000000000000000000000000000000000004d",
    "bar": "0x000000000000000000000000000000000000000000000000000000000000004d",
}

Perhaps there's already a command along these lines that I'm missing? What is the command line workflow you use for this? I'm new to foundry - any advice appreciated!

Additional context

No response