Improve inspect context and detect undefined task logic.

[yogeshgoyal26]

Improvement in inspect context and detect undefined task logic to improve overall execution performance of inspect. Specifically scenarios where the tasks success and failure are moved to same task in the workflow, then in that case the tasks are added to the queue in multiple of 2, which increase the overall time take by inspect method. Below is an example workflow: Task1 - Added 1 time Task2 - Added 2 times Task3 - Added 4 times Task4 - Added 8 times ..

---
version: "1.0"
description: "Test workflow"
input:
- "a1"
- "a2"
tasks:
  Task1:
    action: "core.noop"
    next:
    - when: "<% succeeded()  %>"
      do: "Task2"
    - when: "<% failed() %>"
      do: "Task2"
  Task2:
    action: "core.noop"
    next:
    - when: "<% succeeded()  %>"
      do: "Task3"
    - when: "<% failed() %>"
      do: "Task3"
  Task3:
    action: "core.noop"
    next:
    - when: "<% succeeded()  %>"
      do: "Task4"
    - when: "<% failed() %>"
      do: "Task4"
  Task4:
    action: "core.noop"
    next:
    - when: "<% succeeded()  %>"
      do: "Task5"
    - when: "<% failed() %>"
      do: "Task5"
  Task5:
    action: "core.noop"
    next:
    - when: "<% failed() %>"
      do: "fail"

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:white_check_mark: guzzijones
:x: Yogesh Kumar

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[guzzijones]

This looks good to me.

[arm4b]

@yogeshgoyal26 Looks like we have a Changelog for Orquestra: https://github.com/StackStorm/orquesta/blob/master/CHANGELOG.rst It would be helpful to include a description for this enhancement in there too for completeness.