Describe the bug
As an admin, when trying to import proposals to projects, I can't filter the proposals I want to import by scope.

To Reproduce

1. Go to the "import proposals to projects" page on a Budget component
2. Select a proposal component with scopes enabled to import proposals
3. Select a scope with one accepted proposal related
4. Click on "import proposals to projects"
5. See error

Expected behavior
As an admin, when trying to import proposals to project, I expect to be able to select the scope.s that I want to import.

Screenshots

As an admin, I want to import accepted proposals associated with the "Jeannetteburgh" scope.

So I go on the "import proposals to projects" page, and try to scope my request for "Jeannetteburgh" proposals only.

All accepted proposals are imported as projects, even if the "South Lerashire" sub-scope belongs to another parent scope (see in the filters above).

Extra data (please complete the following information):

• Decidim Version: [Decidim 0.28.0.dev]
• Decidim installation: [https://nightly.decidim.org/]