[Linear] Support Project or Customer Selection when Pushing to Linear

The Linear integration is great so we can push feedback directly into Linear.

The issue is that we Push to Linear, we only have the option to specify the ‘team’ and ‘assignee’. So after we push to Linear, we have to manually go assign it to the correct project.

Now that Linear has ‘Customer requests’ it would also be great to select a customer to push it to so we don’t have to manually go into Linear to adjust afterwards.