enforce max res mins to be greater than or equal to min res mins

issue #73569
fix tests from previous changes; enforce that max_reserve_mins is interval of reserve_interval same as min_reserve_mins

issue #73569
charge_for options should depend on control_mechanism

issue #73569
Display charge_for setting

issue #73569
display rate per minute during price policy setup

issue #73569
charge for at least 1 minute of usage

issue #73569
styling changes to price per minute display on price policy edit
Merge pull request #90 from tablexi/pricing_cleanup_73569

Pricing cleanup 73569