Expand Prefect workflow to incorporate both automatic and interactive modes

[krlberry]

Objective:

From The RADPS Product Roadmap objective, Item 02: Workflow Concept Validation , Number 3 : "Demonstrate how a workflow can be executed automatically and interactively.

Requirements:

• Demonstrate the ability to pause a workflow based on a condition being met, provide input which can be used to modify the a task or flow, and then continue the workflow.
• Document Prefect's current support for interactive modes on a wiki page.

Definition of Done:

• A workflow with the ability to pause at a certain point under specific conditions, accept user input, and then execute conditional code based on the user input provided has been created.
• A wiki page or section of a wiki page which describes the Prefect's capabilities for interactive flows and user interaction.
• Present the interactive workflow

Key Decision Points:

• Which stage or task of the pipeline to add the interactive pause stage
• How to implement interactive vs automatic modes in the same workflow.

[taktsutsumi]

To demonstrate interactivity with the workflow, a separate script, int_clean.py was written, to mimic interactive clean, which allows to pause for user input and change a conditional based on the input within an iteration logic. The code uses the 'solve' function from the imaging stage workflow code. The remaining work to be done is to integrate it into the main workflow, pipeline.py with an ability to switch between automatic and interactive modes.