Update chw-core modules' registers' implementation

[allan-on]

• Goldsmith makes use of thechw-core library which has dependencies with registers implementations.

• These registers implementations need to be updated with new register reconfigurability contract methods implemented or functions refactored to have the correct return types as a result of using the latest client-core library that introduces the registers reconfigurability functionality

• Currently, this blocks using of chw-core in Goldsmith

The following will have to be updated/refactored:

• [x] CHW Family Planning
• [x] CHW ANC
• [x] CHW PNC
• [x] Family
• [x] Core Child
• [x] Malaria

[allan-on]

• [x] Update the client-opd module as well