feat: `vm.blobhashes`

[onbjerg]

Motivation

There is no way to mock blobhashes currently

Solution

Add a cheatcode to set all blobhashes in the transaction. Note that this takes a list of blobhashes, as setting them individually by index would require us to fill the blobhash list with garbage in some cases to grow the list to an appropriate size and avoid a panic.

Closes https://github.com/foundry-rs/foundry/issues/6996

[onbjerg]

Gonna take a while, I have to redo the entire testdata directory since we want to run Cancun separate from every other test, and currently we just compile everything in the testdata directory

[flyq]

Is this pr currently blocked?

[onbjerg]

yes, but not on a feature/pr, just on time. we need to restructure most of our testing suite because we want to test cancun separately

[mattsse]

@yash-atreya this should be unblocked now with cancun specific test setup so ptal

[yash-atreya]

@mattsse ptal