Update Prettier Solidity

[frangio]

The new version of Prettier Solidity changes a few things about how it formats the code, so this PR includes many small changes to formatting.

I wrote a little program to check that files in this PR didn't change in their actual Solidity content, other than comments and whitespace: solidity-fingerprint.

[ernestognw]

Ran tests for both master and this branch.
Everything seems fine 👍

GIst

[Janther]

there are a few scenarios where prettier-plugin-solidity changes the code to improve readability. However we make sure these changes don't affect the compiled code.
For example a * b / c will be formatted as (a * b) / c or a ** b ** c will result in a ** (b ** c).
these changes will generate a different fingerprint in your program since we added () but the compiled code will be the same.
So in the future, when we release a new version, you might want to consider comparing compiled codes instead.

[frangio]

@Janther The issue is that things like abstract contracts don't produce bytecode. But you're right that the fingerprint as I defined it here is not the right approach. Instead of computing a fingerprint of the token stream, it should probably be of the AST.