On outstanding invoices report, add filters

[hagen]

On Outstanding invoices report, the following filters would be useful:

• date range
• practitioner
• patient (free type?)
• business
• invoice paid?
• invoice to (third party payer contact)

Extra info in report

Show number of times emails have been sent for each invoice (counter for patient, counter for other?)

Email all

In addition, mass emailing all invoices listed would be helpful. There are some considerations here.

1. This won't show up in Cliniko's communications
2. Can we invoke Cliniko's send function through XHR?
3. Can't do this for multiple pages... perhaps message that only invoices on the current page will be emailed