Validation error points to an invalid location in the PSL

[pimeys]

Bug description

When having multiple relation constraints with the same name, the validation error points to a wrong location.

How to reproduce

With the following data model:

datasource db {
  provider = "sqlserver"
  url      = "sqlserver://"
}

model A {
  id  Int @id @default(autoincrement())
  bs1 B[] @relation("A1")
  bs2 B[] @relation("A2")
}

model B {
  id  Int @id @default(autoincrement())
  aId Int
  a1  A   @relation("A1", fields: [aId], references: [id], onUpdate: NoAction)
  a2  A   @relation("A2", fields: [aId], references: [id], onUpdate: NoAction)
}

We get validation errors:

Error: error: Error parsing attribute "@relation": Given constraint name is already in use in the data model.
  -->  schema.prisma:1
   | 
   | 
 1 | datasource chinook {
   | ^ Unexpected token.
   | 
error: Error parsing attribute "@relation": Given constraint name is already in use in the data model.
  -->  schema.prisma:1
   | 
   | 
 1 | datasource chinook {
   | ^ Unexpected token.
   | 

Expected behavior

We should point the field or if possible, the map attribute in the field. We should also print the name of the constraint.