Add ability to receive settings via POST

[n0nuser]

Is your feature request related to a problem? Please describe.
It improves flexibility in the Agent execution flow because it allows not to interrupt the program manually and launch it again.

Describe the solution you'd like
Receive settings as JSON. Replace Pydantic for a new designed class.
When new settings are received, refresh the server with the new settings. Authenticate with the agent with a token, else return auth error.