Create a 'related definitions' API

I'm thinking similar to how we do
https://api.clearlydefined.io/suggestions/npm/npmjs/-/glob/7.1.3

We would have another endpoint like
https://api.clearlydefined.io/related/npm/npmjs/-/glob/7.1.3

And this would have an algorithm that returned a list of coordinates.

We can start by returning other revisions of the same coordinates that have the same data missing

For example:

If `npm/npmjs/-/glob/7.1.3` is missing a declared license, return other `npm/npmjs/-/glob/` that are also missing a declared license

If `npm/npmjs/-/glob/7.1.3` is missing a source location, return other `npm/npmjs/-/glob/` that are also missing a source location

```
GET https://api.clearlydefined.io/related/npm/npmjs/-/glob/7.1.3

REPSONSE [ "npm/npmjs/-/glob/7.1.2", "npm/npmjs/-/glob/7.1.0", ... ]
```