* WIP for error boundary support w/ burnettk
* updates to catch error boundary events and send them back out w/ burnettk
* fixed broken test w/ burnettk
* use connector-http and spiffworkflow-proxy from main w/ burnettk
* updated smtp and slack connectors in connector-proxy-demo w/ burnettk
* added more tests for the service task service call connector to test errors w/ burnettk
* added spiffworkflow-connector-command and some code clean up
* updated the connectors in the proxy demo
* use SpiffWorkflow from git instead of locally
* some cleanup while code reviewing
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Co-authored-by: jasquat <jasquat@users.noreply.github.com>