[Fleet] APIs - WIP

[mattapperson]

Auth methods

Method	Existing?	Details
Enrollment key	No (#40976)	A key that is of general use for enrollment. Created per config. It can be regenerated at anytime, but this invalidates the previous token
Authentication Token	Yes (from CM)	A JWT based token (for easy debugging) that is generated per-agent at enrollment time that is used to authenticate each request made by an agent to Kibana
User: fleet permissions	No (#38576)	A user with administrative privlages assigned via Kibana feature controls (idealy, TBD)
User: cluster privlages	Yes	A user with administrative privlages assigned via Kibana feature controls (idealy, TBD)

Fleet API

• Enrollment key [Fleet] Enrollment key API #40962
• Enrollment Rules [Fleet] Enrollment rules API #40963
• Agents [Fleet] Agents API #40964
• Check-in [Fleet] Check-in API #40965
• Install.sh [Fleet] Install.sh API #40967

Ingest Manager API

• Config [Ingest Plugin] Config API #40968
• Outputs [Ingest Plugin] Outputs API #40969
• Assets [Ingest Plugin] Outputs API #40969