[NM-71] Ensure that download result polling is stopped when outputs are reset

[r-ash]

Description

We can get into a state where the app will poll the download status without an ID repeatedly. To recreate

1. Go to the “Save resutls” stage on a project, wait for status poll to begin
2. Go back to an earlier step and change something which invalidates the later steps e.g. change a model option
3. See that the app will continue to poll /download/status without an ID

When the download step is invalidated, we should cancel any polling

Type of version change

Patches

Checklist

• I have incremented version number, or version needs no increment
• The build passed successfully, or failed because of ADR tests

[M-Kusumgar]

LGTM! happy to approve this for now, i want to test it out but slow internet XD but yh will async run up the app and test

edit: can confirm i dont see the polling

[notion-workspace]

Stop app eternally polling download status