Expose current locale to filterOptions callback

[felskov]

I'd like to be able to access current locale in filterOptions callback on a collection, e.g. like this:

{
  name: "reference",
  label: "Document to link to",
  type: "relationship",
  relationTo: [
    "pages",
    "galleries"
  ],
  required: true,
  maxDepth: 1,
  filterOptions: ({ relationTo, locale }): Where => {
    if (relationTo === "pages") {
      // allow linking only to pages written in the currently selected locale
      return {
        locale: {
          equals: locale,
        },
      };
    }

    return {};
  },
},

I've had a look and think that this should be rather trivial to implement here:
https://github.com/payloadcms/payload/blob/04850694c1cfa13279b80f5d195a5eeeedd815e9/packages/payload/src/admin/components/utilities/GetFilterOptions/index.tsx

Let me know if you'd be interested in me opening a PR for this change.