Dashboard to show update available for remote packages

**Describe the problem you have/What new integration you would like**

I am developing a device based on ESPHome that I intend to make available for others to use, following the examples given here https://esphome.io/guides/creators.html I have used the `dashboard_import` `package_import_url` to point to the github repo containing my configuration files.

My configuration files contain a project version as detailed here https://esphome.io/components/esphome.html?highlight=project#esphome-creators-project

It would be great if the dashboard showed an update button when there was a difference between the version on the esp32 and the version published on Github. This would provide a way of notifying users of the project that there is an updated configuration available without need to rely on other means of notification/users never knowing there's new features

**Please describe your use case for this integration and alternatives you've tried:**

Making sure that users are aware of configuration updates which might include bug fixes without needing to post on social media and hope people see it

**Additional context**

Start by tracing how the dashboard handles dashboard_import and package_import_url, then review the project-version information described in the linked ESPHome documentation. Define how the dashboard should compare the ESP32 version with the GitHub-published version and what the update action should do; done means users can see and act on an available configuration update.

Written by the indexing model from the issue text.