New feature

This PR introduces the new tmctl import command that would allow users to share their integrations.

Sample flow

1. Create an integration:
   1.1 start the broker

   tmctl create broker foo
   

   1.2 create the source (AWS SQS for example)

   tmctl create source awssqs --arn arn:aws:sqs:eu-central-1:000000000000:foo-queue --auth.credentials.accessKeyID <redacted> --auth.credentials.secretAccessKey <redacted>
   

   1.3 create the target (eg. sockeye)

   tmctl create target --from-image docker.io/n3wscott/sockeye:v0.7.0  --name sockeye
   

   1.4 create the transformation to complete the flow

   tmctl create transformation --source foo-awssqssource --target sockeye <<EOF
   data:
   - operation: add
     paths:
     - key: new-field
       value: hello from Transformation!
   EOF
   

2. Export the integration:

tmctl dump --no-secrets > foo-integration.yaml

tmctl dump without --no-secrets flag will produce the manifest with AWS SQS credentials. Be careful with sharing those.

2.1 (Optional) Replace arn:aws:sqs:eu-central-1:000000000000:foo-queue in the foo-integration.yaml with <user_input> to request SQS queue ARN on import.

3. Send foo-integration.yaml to someone who wants to run the integration on their machine or upload it as gist.

4. On receiving side, just execute tmctl import -f <path/url>, type in requested values (creds, arns), start the integration. Sample manifest with the described integration can be imported from the public gist:

tmctl import -f https://gist.githubusercontent.com/tzununbekov/c19c68706004f92f354bfb2fce49b705/raw/60f495cd7bce0dac94a5dd1d68031c3def9813b8/foo-integration.yaml
tmctl start foo