[cms] Notify to submit invoice earlier and more intense

[xaur]

Currently CMS notifies contractors on 5th, but there is no good reason to not notify earlier.

I suggest to send the first notification on 1st, or even on the last day of the previous month (because people don't immediately react so notifying in advance won't hurt).

Also I suggest to add more notifications, e.g. second one on 4th and third one on 7th.

[alexlyp]

Sounds great will add it.