Delete old deployments automatically

Some projects may have 100000+ deployments, which can cause different performance problems. #342715 (closed) was caused by the project having almost half a million old production deployments. We can optimize all the SQL queries, but over time every feature using deployments will become slower + it will take a significant space in our database.

We can:

1. Allow users how many/for how long deployments they want to keep for the single environment.
2. Automatically remove all older environments