Add recommendations if there is a missing file

[montyly]

A lot of users issues are related to errors like
crytic_compile.platform.exceptions.InvalidCompilation: Unknown file: @openzeppelin/...

Which is usually a sign that npm install/yarn install had an issue, or the files where installed somewhere else. We could improve the error message with recommendations like:

• Check if ls <path to file>
• Run npm install / yarn install