feat(launchpad): adding a launchpad to control flagd

[aepfli]

how to test

# building docker image
docker build --target=testbed -t=flagd-testbed-new -f ./flagd/Dockerfile .
# running docker image
docker run --rm -p 8080:8080 -p 8013:8013 -p 8015:8015 flagd-testbed-new

curl command to fetch changing flag

 curl -X POST "localhost:8013/flagd.evaluation.v1.Service/ResolveString" -d '{"flagKey":"changing-flag","context":{}}' -H "Content-Type: application/json"

you can start/stop based on the endpoints provided, or change the flag and verify with the above curl command if it works or not. (either via browser or curl) http://localhost:8080/[start|stop|change](?config=(default|ssl))

[aepfli]

closes #190

[toddbaert]

I think we may as well delete the wrapper.