allow using `use x as y;` in q! macro

[luckyworkama]

while trying to use use x as y; in a q! macro i got this error:

error[E0432]: unresolved import `x__free`
  --> hydro_lang/src/live_collections/keyed_stream/mod.rs:1416:17
   |
16 |             use x as y;
   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no external crate `x__free`