chg: generate, cleanup: Use 28 days of measurements

When generating the Bandwidth File as Torflow, use 28 days of past raw
measurements instead of 5, by default.
Also keep the raw measurements for that long before compressing or
deleting them.
And stop checking whether the compression and delete
periods are valid, without checking defaults first and based on
arbitrary values.

Closes: #40017
7 jobs for maint-1.1_issue40017_01 in 35 minutes and 20 seconds (queued for 5 minutes and 11 seconds)