Feature: Override calldata

[shazow]

Maybe an advanced mode where you can override the calldata with something specific, the rest of the decoding becomes readonly?

(Right now it's the reverse: Calldata is readonly, generated from the inputs)

[shazow]

@IDEA-godwin if you're interested in working on something else, this might be a good one. I imagine clicking on the readonly calldata block (or having an [Edit Calldata] button or something?) would switch to calldata editing mode, make it writeable, then once you hit [Save Calldata] or something, it re-parses the calldata (as it would normally from the URL) and sets the correct state.

[IDEA-godwin]

Sounds interesting, would get to it.