[PM-7186] Cancel the Extension when an exception occurs

[dinisvieira]

Type of change

• Bug fix
• New feature development
• Tech debt (refactoring, code cleanup, dependency upgrades, etc)
• Build/deploy pipeline (DevOps)
• Other

Objective

Currently the Autofill Extension can get stuck in a Loading if an exception occurss.
We also suspect there might be other errors causing our extension to get disabled by Apple and/or the ASStore to be deleted.
This is still under investigation.

Code changes

• LoginListViewController.cs: Added Cancel after showing error to user. This way the Extension closes gracefully

Before you submit

• Please check for formatting errors (dotnet format --verify-no-changes) (required)
• Please add unit tests where it makes sense to do so (encouraged but not required)
• If this change requires a documentation update - notify the documentation team
• If this change has particular deployment requirements - notify the DevOps team