Improve support for entities with `id: number`

[queicherius]

You can currently use numeric IDs / cursors, but you have to manually pass the generic: https://github.com/devoxa/prisma-relay-cursor-connection/blob/master/tests/index.spec.ts#L194

//                                            v Model type
const result = await findManyCursorConnection<User, { id: number }>(
//                                                    ^ Cursor generic

You can also not use select or include, because of the manually provided generics.

With some TS magic (that I could not figure out so far) it might be possible to make this automatically infer the correct types.

If someone want to take a stab at it, I provided some additional tests & type checks on the https://github.com/devoxa/prisma-relay-cursor-connection/tree/fix-generics-with-number-id-2 branch. The tests already pass (as expected) but the type checks in the test file do not.

[rjhilgefort]

I know GitHub links it in the issue references / activity, but I wanted to explicitly call out the original issue I raised for this effort. It has some context that might be helpful for others arriving at this issue down the road.

#938