Heathcare : Hl7 messages to HL7v2 Store (HCAPI) example (#28873)

* Adding examples to post messages hl7 messages to HCAPI Hl7v2 store

Adding beam example on consuming HL7 message file from GCS bucket , transform it and post HL7 messages to HCAPI Hl7v2 store for further ingestion and consumption

* Created using Colaboratory

* Update examples/notebooks/healthcare/beam_post_hl7_messages_to_hcapi.ipynb

Co-authored-by: Svetak Sundhar <svetaksundhar@google.com>

* Update examples/notebooks/healthcare/beam_post_hl7_messages_to_hcapi.ipynb

Co-authored-by: Svetak Sundhar <svetaksundhar@google.com>

* Update examples/notebooks/healthcare/beam_post_hl7_messages_to_hcapi.ipynb

Co-authored-by: Svetak Sundhar <svetaksundhar@google.com>

* Created using Colaboratory

* Created using Colaboratory

* Created using Colaboratory

* Created using Colaboratory

* Created using Colaboratory

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Co-authored-by: Svetak Sundhar <svetaksundhar@google.com>

Author: devanshmodi