[ ] I have added to CHANGELOG.md relevant changes and any other user facing change
[x] I have added or ran the appropriate tests
What this PR does / why we need it:
The PR adds a new Mix task for the Astarte Dev tool that opens an authenticated Astarte Dashboard session in the browser.
This comes in handy when, after starting up the Astarte containers with Docker Compose, one wants to quickly opens the Dashboard without manually generating the token with appropriate permissions, navigating to the Dashboard URL, and filling in the required fields to sign in.
What this PR does / why we need it:
The PR adds a new Mix task for the Astarte Dev tool that opens an authenticated Astarte Dashboard session in the browser.
This comes in handy when, after starting up the Astarte containers with Docker Compose, one wants to quickly opens the Dashboard without manually generating the token with appropriate permissions, navigating to the Dashboard URL, and filling in the required fields to sign in.