State variables don't respect module namespaces

[shonfeder]

Given

module A {
  var x: int
}

module B {
  var x: int
}

module C {
  import A
  import B
  action step = all {
    A::x' = A::x,
    B::x' = B::x,
  }
}

We get

$  quint typecheck t.qnt 
t.qnt:2:3 - error: [QNT202] Multiple updates of variable x
2:   var x: int
     ^^^^^^^^^^

t.qnt:6:3 - error: [QNT202] Multiple updates of variable x
6:   var x: int
     ^^^^^^^^^^

error: typechecking failed

But I would expect these variables to be completely distinct.

On the face of it, this looks to me like an iteration of the general namespacing motif from #1288.

[bugarela]

Oh right. My solution considered only instances, but this should also include namespaces. I'm afraid this will be more complicated to fix, tho. We'll figure something out.