at_c: verbbuilders in packages/atcommons

[JeremyTubongbanua]

Implement VerbBuilders, just like how we have in our at_java and Dart at_client_sdk SDKs.

It is a common pattern to do atProtocol operations like update:<..> and llookup:<..>. seeing that this is a common pattern, current CRUD and notification operations should be refactored and utilize verb builders.

I am justifying this as "P3 - Nice to have" because it isn't core to the SDK's functionality

This should go in packages/atcommons to be utilized as a dependency by atclient and atauth

Tasks

Beta Give feedback

1. Create verb_builders.h
2. Create verb_builders.c
3. atclient_verb_builders_build_update
4. atclient_verb_builders_build_scan
5. atclient_verb_builders_build_llookup
6. atclient_verb_builders_build_lookup
7. atclient_verb_builders_build_plookup
8. atclient_verb_builders_build_notify
9. atclient_verb_builders_build_monitor
10. atclient_verb_builders_build_from
11. atclient_verb_builders_build_pkam
12. atclient_verb_builders_build_cram
13. atclient_verb_builders_build_delete
14. atclient_verb_builders_build_enroll
15. atclient_verb_builders_build_update unit tests
16. atclient_verb_builders_build_scan unit tests
17. atclient_verb_builders_build_llookup unit tests
18. atclient_verb_builders_build_lookup unit tests
19. atclient_verb_builders_build_plookup unit tests
20. atclient_verb_builders_build_notify unit tests
21. atclient_verb_builders_build_monitor unit tests
22. atclient_verb_builders_build_from unit tests
23. atclient_verb_builders_build_pkam unit tests
24. atclient_verb_builders_build_cram unit tests
25. atclient_verb_builders_build_delete unit tests
26. atclient_verb_builders_build_enroll unit tests

Function signature would look something like this:

int atclient_verb_builders_build_put(char **output, const atclient_atkey *atkey, const char *value);
int atclient_verb_builders_build_scan(char **output, const char *regex, const bool show_hidden);
// ...

[JeremyTubongbanua]

Backlogging since this is unimportant for C Daemon