Improve syntax highlighting

[kanej]

This is an investigation task, can we be deliberate about improving our syntax highlighting, rather than relying on ad-hoc bug reports to make changes.

The first part of the investigation is to assess the quality of our current support:

• How do we compare with Solidity by Juan Blanco/vscode-solidity-extension by ContractShark
• VIM syntax highlighters
• Intellij (Textmate grammar)

The second part is to investigate whether we can leverage slangs canonical representation of the syntax.

Once this investigation is complete we can break down further tasks

[kanej]

We should look at how good our Yul support is in particular.

[tinchoabbate]

+1 to supporting syntax highlighting in Yul