Refactor `find_org_coc` method

[MichaelJamesParsons]

Description

The find_org_coc() function returns a models::ChainOfCommand struct that represents the org's CoC in two separate lists: extended_coc and local_coc. Refactor this method to return a single list ordered by the org's CoC.

[...localCoc, ...parentCoc, ...grandparentCoc, ...]

Additionally, the function eager loads associations. Refactor the code so eager loading is handled by the function callers instead of internally. Long term, eager loading will be extracted from all model functions.