Add instrumentation for MAU visiting environments pages

What does this MR do and why?

This adds a new instrumentation to count MAU users visiting a project environments pages (i.e. all /-/environments/* paths).

We use a Redis HLL counter to count unique visits to the following actions in the Projects::EnvironmentsController:

• index
• folder
• show
• new
• edit
• create
• update
• stop
• cancel_auto_stop
• terminal

And ProductAnalyticsTracking is used instead of RedisTracking because the use of track_redis_hll_event directly is deprecated in favour of using track_event instead.

Resolves #355690 (closed).

How to set up and validate locally

1. Generate a service ping payload from Admin > Settings > Metrics and Profiling > Preview Payload
2. Notice the new users_visiting_environments_pages_monthly key.

MR acceptance checklist

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