Show the file path rather than module name when reporting contract violations

[mangin]

Hi there,

I would like to see in the error output where the error happens.
now we print only module package and external tools can't work nicely with it and be honest for humans it's hard to map module to the particular place too.

I tried to understand why it was implemented like this. and i think that the root of this decision goes to grimp.
But have you thought about moving to file location based errors from package based?

[seddonym]

Thanks for raising - there is already some work on this in #288.

I'll leave this open though as I don't think that PR has an accompanying issue.