Add contractClass interpretation to address values

[haltman-at]

PR description

Addresses #5913. Adds a contractClass interpretation to address values. Basically, if we can identify what sort of contract a given address is, it will have this interpretation with more information; otherwise it won't.

Yes, this means that the address/contract distinction is now pretty silly -- they now contain the same information but formatted differently. Oh well. I don't want to make a breaking change to make them more unified.

The code is pretty straightforward, not much to explain. I could have further eliminated some minor recomputation by just using decodeContract and then doing everything based on the results of that, but I decided it was clearer to do it this way, even if that means calling Evm.Utils.toAddress twice. :P

I also updated the inspector so that it now basically just treats addresses like contracts. Could have distinguished them some but that would have been more work.

I did not update codec-components. I figure I can worry about that later; there are likely multiple changes I want to make to address and contracts there.

Testing instructions

I added a debugger test for it, I figured that should be enough.

[cliffoo]

Makes sense! Although maybe someone else should take a look also...