fix: relation count on self m2m

[Weakky]

Overview

Fixes prisma/prisma#7807
Fixes prisma/prisma#7893

As we perform inner joins on both sides in the case of an m2m, this PR adds aliases to the joins so that the same table is not referred to twice in the same block.

Example

Given this datamodel:

model User {
  id Int @id @default(autoincrement()))
  following User[] @relation(name: "approved-followers")
}

And the following query:

query {
  findManyUser {
    id
    _count {
      following
    }
  }
}

Here's what the LEFT JOIN in charge of computing the count aggregation would look like before:

LEFT JOIN (
  SELECT
    "public"."User"."id",
    COUNT(*) AS "_aggr_count_following"
  FROM
    "public"."_approved-followers"
      INNER JOIN "public"."User" ON ("public"."User"."id" = ("public"."_approved-followers"."B"))
      INNER JOIN "public"."User" ON ("public"."User"."id" = ("public"."_approved-followers"."A"))
	GROUP BY "public"."User"."id"
) AS "aggr_selection_0_User" ON ("public"."User"."id" = "aggr_selection_0_User"."id")

And after (notice the aliases on the INNER JOINs):

LEFT JOIN (
  SELECT
    User_A."id",
    COUNT(*) AS "_aggr_count_following"
  FROM
    "public"."_approved-followers"
      INNER JOIN "public"."User" AS User_A ON (User_A."id" = ("public"."_approved-followers"."B"))
      INNER JOIN "public"."User" AS User_B ON (User_B."id" = ("public"."_approved-followers"."A"))
	GROUP BY User_A."id"
) AS "aggr_selection_0_User" ON ("public"."User"."id" = "aggr_selection_0_User"."id")