Feature request: Allow setting custom context

[Mouradif]

I'm following up on issue #287

It would be great if we could set a custom context before running the transaction. To be able to customize

• block number
• block timestamp
• msg.sender
• tx.origin

These are all I can think of at the moment (and that I actually needed for a specific debugging task)

[dorlevi]

it's in our backlog but between evm.storage work and our new product it hasn't come to the top of the list just yet, we are always open to additions from the community and will review and work to merge your PR if others post one.