Add CHW identifier to Events

[allan-on]

• For the Supervisor to view their CHW's performance defined by the indicator queries, the events generated when a CHW does a visit or registers a child need to have the CHW's identifier.

• This identifier is what will be used to filter the events for counts on the Supervisor app when the supervisor navigates to a CHW Profile.

Process

• Add CHW practitioner identifers to the details object on the event
• update the ec_child & anc_register tables to the practitioner_identifier column. Probably write migrations for this.
• Update the client sync processor to populate the above table.