DP-685: Update component diagrams

[jakzal]

I opted to document abstractions rather than concrete implementations in most cases. Specifically, instead of documenting every possible endpoint and use case, they're represented by a single component - "Endpoint", "UseCase", etc. This way it's:

• easier to maintain as we don't have to update diagrams each time we add a new component (if we wanted go this route it would be easier to generate these based on code)
• easier to read as there's less clutter on diagrams

Authority

Organisation App

Tenant Api

Person Api

Organisation Api

Forms Api

Data Sharing Api

Entity Verification