Publish download statistics for Library Manager libraries

### Describe the request

Please publish the number of installations for each of the Library Manager libraries.

This information would be useful to users as a metric when evaluating library candidates for use in their projects.

This information would be useful to library developers as a metric for prioritizing their development resources to libraries that are most important to the Arduino ecosystem.

### Additional context

#### Additional requests

- https://github.com/arduino/arduino/issues/5368
- https://github.com/arduino/Arduino/issues/7265#issuecomment-2352457357
- https://github.com/arduino/Arduino/issues/9774
- https://github.com/arduino/Arduino/issues/11147
- https://github.com/arduino/library-registry/issues/894
- https://groups.google.com/a/arduino.cc/g/developers/c/DXnt16Cn-WI
- https://groups.google.com/a/arduino.cc/g/developers/c/_g-uvtqg1tg/m/hbRgoybNCAAJ
- https://groups.google.com/a/arduino.cc/g/developers/c/_g-uvtqg1tg/m/tq6RDbCoBQAJ
- https://groups.google.com/a/arduino.cc/g/developers/c/_g-uvtqg1tg/m/s8m5ZcnbAAAJ

#### Related

- https://youtu.be/Xa0WjwDdHaM?t=3628
- https://groups.google.com/a/arduino.cc/g/developers/c/_g-uvtqg1tg

No source files, tests, or entry points are identified in the issue. Start by reviewing the linked related issues and developer discussions to determine where Library Manager installation data comes from and how it should be published; done requires an agreed design and a defined statistics interface.

Written by the indexing model from the issue text.