Add SHA-256 hashes to file lists in solc-bin

[cameel]

Proposed by @axic in #10352 (comment).

Hmm, didn't we also had a sh256 hash next to this? That is way more useful for anyone downloading a static compiler from here and trying to verify it on CI (as that works with shasum -a 256 ).

After doing this the example in solc-bin docs should be updated to include such a hash too.

[rainbreak]

Yes please, it's way easier to deal with sha256. In particular, NixOS requires a sha256 when fetching a url and can't accept keccak256, so I have to manually calculate the sha256.

[axic]

Finally found that I actually did this years ago, that's why I was confused in the opening comment why it wasn't done: ethereum/solc-bin#19 (commit dcbf73d)