Support output strategies in pipeline code

[dominikriemer]

Purpose

Support custom and user-defined output strategies in the pipeline-as-code model.

Example:

id: test
name: Test
description: ""
pipelineElements:
  - type: stream
    ref: 0_6fSh
    id: sp:spdatastream:Kmneup
  - type: processor
    ref: 1_ScpA
    id: org.apache.streampipes.processors.filters.jvm.project
    connectedTo:
      - 0_6fSh
    configuration: []
    output:
      keep:
        - s0::timestamp
        - s0::volume_flow
  - type: processor
    ref: 2_QGAv
    id: org.apache.streampipes.processors.enricher.jvm.jseval
    connectedTo:
      - 1_ScpA
    configuration:
      - jsFunction: >-
          function process(event) {
              // do processing here.
              // return processed event.
             // Type 'event' and press Ctrl+Space to see available fields.
             // Example: 
              return {timestamp: event.timestamp, tempInCelsius: (event.tempInKelvin - 273.15)};
          }
    output:
      userDefined:
        - fieldName: timestamp
          runtimeType: http://www.w3.org/2001/XMLSchema#long
          semanticType: http://schema.org/DateTime
        - fieldName: volume_flow
          runtimeType: http://www.w3.org/2001/XMLSchema#float
          semanticType: http://schema.org/Number
        - fieldName: volume_flow2
          runtimeType: http://www.w3.org/2001/XMLSchema#float
          semanticType: http://schema.org/Number  
  - type: sink
    ref: 3_9Wl9
    id: org.apache.streampipes.sinks.internal.jvm.datalake
    connectedTo:
      - 2_QGAv
    configuration:
      - timestamp_mapping: s0::timestamp
      - db_measurement: asddd2
      - schema_update: Update schema
      - dimensions_selection: []
      - ignore_duplicates: false
createOptions:
  start: false

Remarks

PR introduces (a) breaking change(s): no

PR introduces (a) deprecation(s): no