Project name file should use extension

[seadowg]

The project name file (the blank file we write into the project dir with the same name as the project) should have an extension that lets Collect and the user identify that that's what it is. At the moment it would be risky to generate this file on demand as we don't know if the files in the root of the project dir are project name files or not (so can't really just delete them).

Acceptance

• [ ] Given I've created a project When I view the project dir in Device File Explorer or ADB Then it contains a file named <project name>.name

• [ ] Given I've created a project When I change the project name And I view the project dir in Device File Explorer or ADB Then it contains a file named <project name>.name And it does not contain another .name file

Notes

In terms of implementation for this, we could always have the file creation/rename happen in StoragePathProvider and just do it on demand. We should probably make this work async (using Scheduler) so we avoid it adding any I/O to calls that are accessing the project dir. This should allow us to get rid of the UpdateProjectTest#updateProjectName_updatesProjectNameFileSanitizingIt test.

[seadowg]

@lognaturel can you see any problems with doing this?