Provide best-effort links to contents in `node_modules`

In cases where an error is reported from a file in node_modules, we end up with output like the following:

packages/utils/devEnv/tsconfig.json

• error TS2694: Namespace '"/mnt/ts_downloads/_/m/theatre/node_modules/@types/estree/index"' has no exported member 'StaticBlock'.
  • file:///mnt/ts_downloads/_/m/theatre/node_modules/@types/eslint/index.d.ts#L617
  • file:///mnt/ts_downloads/_/m/theatre/node_modules/@types/eslint/index.d.ts#L618
• error TS2300: Duplicate identifier 'ElementType'.
  • file:///mnt/ts_downloads/_/m/theatre/node_modules/@types/hoist-non-react-statics/node_modules/@types/react/index.d.ts#L3244
  • file:///mnt/ts_downloads/_/m/theatre/node_modules/@types/react/index.d.ts#L3244
• error TS2300: Duplicate identifier 'LibraryManagedAttributes'.
  • file:///mnt/ts_downloads/_/m/theatre/node_modules/@types/hoist-non-react-statics/node_modules/@types/react/index.d.ts#L3254

I think it would be helpful if we could provide a link to the exact version on unpkg, or more ideally, GitHub if we could really figure that out.

The issue names no implementation files or tests. Start by locating the code that formats compiler-error file links, then determine how dependency versions and repository locations can be resolved; done means node_modules locations receive best-effort links to the matching unpkg or GitHub contents.