Page view stats

What does this MR do and why?

Add a counter on resource pages to display the amount of time the resource was shown to a user.

feat(stats): Add page view statistics

Screenshots or screen recordings

How to set up and validate locally

• Install a Redis instance
• Export PM_REDIS_URI and PM_STATS_ENABLED=True

MR acceptance checklist

• My code follows the style guidelines of this project
• I ran pylint and other linters for modified files
• I have performed a self-review of my own code and tested it
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• My code needed automated testing. I have added them (this is optional task)
• I have added user readable comment in the CHANGELOG