Support for checking `require.resolve()`

[daltones]

Sometimes I use require.resolve() just to resolve paths to other resources than javascript modules.

Okay, this is not a regular import, but it would be nice if this plugin could also check these paths.

Maybe it could be a new setting like 'import/check-require-resolve': true, whereas various rules related to CommonJS imports also apply here.

[benmosher]

I think it could be just a new mode for import/no-unresolved, and could be on by default. Makes sense to me. 😄

[benmosher]

FYI to potential implementors: this should go in utils/moduleVisitor as an enhancement to the exist CommonJS require visitor.