Report invalid `module` field in `package.json`

Some packages define the top-level `module` field in `package.json`. Although it’s non-standard, bundlers use it. This can lead to differences between usage in the browser and Node.js, but it is not possible to add type definitions for it.

I think it would be useful to report the `module` field if it does not match the `import` condition in the `package.json` `exports` field nor the `main` field.

For example:

- [`monaco-editor`](https://github.com/microsoft/monaco-editor/blob/main/package.json#L34)
- [`vscode-json-languageservice`](https://github.com/microsoft/vscode-json-languageservice/blob/main/package.json#L7)
- [`vscode-uri`](https://github.com/microsoft/vscode-uri/blob/main/package.json#L8)
- [`whatwg-fetch`](https://github.com/JakeChampion/fetch/blob/master/package.json#L6)

Start by tracing how package.json metadata is analyzed, focusing on the module, exports import condition, and main fields described here. Done means packages where module disagrees with those fields are reported, with the listed example packages useful for checking the behavior.

Written by the indexing model from the issue text.