Add Canary deployments

[Samze]

New Baras test - https://github.com/cloudfoundry/capi-bara-tests/pull/101

Closes #3837

Trying it

cf push dora -i 2

# Trigger a canary deploy
deployment_guid=$(cf curl -X POST /v3/deployments -d "{ \"strategy\": \"canary\", \"relationships\": { \"app\": { \"data\": { \"guid\": [\"$(cf app dora --guid)\"] } } } }" | jq -r .guid)

# Observe that a new canary web process starts
cf apps

# Observe the deployment is in state paused
cf curl  /v3/deployments/$deployment_guid | jq .status

# Continue the deployment
cf curl -X POST /v3/deployments/$deployment_guid/actions/continue

# Observe as the canary app is rolled out and old processes are removed
watch cf apps

• [x] I have reviewed the contributing guide

• [x] I have viewed, signed, and submitted the Contributor License Agreement

• [x] I have made this pull request to the main branch

• [x] I have run all the unit tests using bundle exec rake

• [ ] I have run CF Acceptance Tests

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• :white_check_mark: login: Samze / name: Sam Gunaratne (41d89731dc6208d6e1d47380762924bd5e56a261, fda1d355d3bf5562a5f767b3c3dd79565c583283, 25862e0eaf55c84ea7e9ca22a81e0511e8ee0f17, 39fb1fcbe2462656dce02f219d289d228931127b, 563bd95af87441a0519e4e70ca9fa7bd817d124e, ec9f2bfd476723face235e8acdd832f7ec99f1ef, 371b29a39ff61a7970fb45d570242fe7d7a654be, fc967d2f7ec90ada0d1ee9eede14a60a1650b2d6, 42a85e77535c5caa795c61a02320ca636983ab67, 4fc1d7cac9c29af1166012313eae420ec4845357, 3a1fcde075ee6962ddf574ecaab0bcda1572101d, 0a978fae16014e1d23694abba9fadda1912b3d52, bd8729220b59d6ff204f8473456f160d25d46c99)