PSL should support inline // comments in the generator and datasource blocks

[jkomyno]

As @tomhoule said, "comments have to be handled in a case-by-case basis in the AST, and we may not have a rule allowing trailing comments inside config blocks".

prisma validate would fail with this simple schema because of the inline comment (placed at the end of a field):

datasource db {
  provider             = "postgres"
  url                  = env("TEST_POSTGRES_URI")
  referentialIntegrity = "prisma" // = on or set to "foreignKeys" to turn off emulation
}

generator js {
  provider        = "prisma-client-js"
  previewFeatures = ["referentialIntegrity"]
} 

The error would be something like the following:

❯ npx prisma validate
Prisma schema loaded from schema.prisma
Error: Get DMMF: Schema parsing - Error while interacting with query-engine-node-api library
Error code: P1012
error: Error validating: This line is not a valid definition within a generator.
  -->  schema.prisma:9
   | 
 8 |   previewFeatures = ["referentialIntegrity"]
 9 |   referentialIntegrity = "prisma" // = on or set to "foreignKeys" to turn off emulation
10 | } 
   |

If however, we get rid of the comment (preserving the rest of the field definition as it is), everything is fine:

-  referentialIntegrity = "prisma" // = on or set to "foreignKeys" to turn off emulation
+  referentialIntegrity = "prisma"

❯ npx prisma validate
Prisma schema loaded from schema.prisma
The schema at /.../schema.prisma is valid 🚀

[tomhoule]

note: this applies only to trailing comments after a key-value pair inside a config block (generator or datasource)