panic when referencing reexported UDT from another package

[minestarks]

When a package references a re-exported UDT from a dependency, a panic occurs:

panicked at `compiler/qsc_frontend/src/typeck/convert.rs:123:13:
internal error: entered unreachable code: A path should never resolve to a local or a parameter, as there is syntactic differentiation.

This bug occurs if we try to use TestCaseResult from qtest package today (but you have to work around #1955 first)

qsharp/library/qtest/src/Main.qs

Line 4 in 6d83547

export Util.TestCaseResult;

REPRO

We need two Q# packages for this:

dep/qsharp.json

{}

dep/src/Main.qs

namespace Foo {
    struct MyType { a: Int }
}

namespace Main {
    export Foo.MyType as MyType; // work around https://github.com/microsoft/qsharp/issues/1955 by using an alias
}

main/qsharp.json

{
  "dependencies": {
    "dep": {
      "path": "../dep"
    }
  }
}

main/src/Main.qs

operation Main() : Unit {
    let x = new dep.MyType { a = 1 };  // this usage triggers the panic
}

panicked at compiler/qsc_frontend/src/typeck/convert.rs:123:13:
internal error: entered unreachable code: A path should never resolve to a local or a parameter, as there is syntactic differentiation.

Seen in 2a4c335