Allow configuring which OpenMRS Encounter are sent to CHT

[witash]

Currently, all encounters from OpenMRS are forwarded to CHT, with the form name hardcoded to openmrs_anc.

1. not all encounters necessarily need to be forwarded to cht, only those that have a corresponding input form on the cht side
2. for those encounters that should be sent, the form name in cht should be based on the form or encounter type from OpenMRS, instead of hardcoded.