Support an additional manual circuit breaker

[dlvenable]

Is your feature request related to a problem? Please describe.

Initially, I'd like to be able to test the circuit breaker behavior using manual controls. Additionally, there may be value in stopping a pipeline temporarily.

Describe the solution you'd like

Provide an HTTP endpoint for opening and closing a circuit breaker.

First, it should be enabled in data-prepper-config.yaml:

circuit_breakers:
  http_forced:
    enabled: true

Then to open the circuit breaker:

curl -X POST http://localhost:4900/circuit_breaker/forced

Then to close the circuit breaker:

curl -X DELETE http://localhost:4900/circuit_breaker/forced

Describe alternatives you've considered (Optional)

Provide a full override of all circuit breakers. But, this could result in running out of memory.

I'd like to see if there is a better name. Right now, I'm calling it "forced," but I think we could do better.

Another idea would be to set the circuit breaker with a timeout. I tend to think this might be a completely different circuit breaker so that the forced one is not interfered with.