Handle sample projects

With the introduction of projects with #90, viewing a service on the map causes a project to be saved.
Saving a project and creating a service are 2 distinct actions and to avoid having the user press multiple buttons, both actions are carried out on Save.

This caused the sample projects to also be saved to the user account when one is selected to view.

We could add some logic so that when a sample project is loaded, the service is created without saving, and then the save button becomes active as soon as there is some change (however the change may be as small as a map pan, which maybe is unexpected)
We could also keep it as is and warn the user that selecting a sample will create a project.

cc @olafveerman @ricardoduplos

Start by reproducing the sample-project selection flow on the map and inspect how project loading, service creation, and Save are connected. Decide whether sample projects should defer saving until an explicit change or warn before creation; done means selecting a sample no longer silently creates a project in the user's account.

Written by the indexing model from the issue text.