[KED-2492] Update store functions for new modular pipeline data

[studioswong]

Description

related ticket: KED-2492

This is the initial set up work to update the store functions to allow the newly added modular_pipeline field from the pipeline data to be added in the state as well ( as a seperate field as well as part of the node data)

Development notes

I have added:

1. A new modular_pipeline field under the state to store the modular pipeline data ( naming following how we named 'pipeline), and a new modular_pipelinesfield for the node state data ( naming of this field also following the pattern of how other fields are name for the node fields, such aspipelines`)
2. A addModularPipeline function to add the modular pipeline by id - it will also check if any existing modular pipelines with the same id exists.
3. Modified the reducer to include the newly added modular pipeline field in the state
4. tests to test the newly added modular pipeline field.

Please note that I had not added any tests relating to the addition of the modular_pipelines field in the node as I observed that there are no existing test to test the specifics of addNode function (nor any node data) within normalize-data.js - in following the existing pattern in the codebase, the existence of this additional field will be covered by further tests set up under the tests for the selectors that will be set up in the ticket for the proceeding work under KED-2436

QA notes

This could be tested by testing the state data after the pipeline data has been loaded.

Checklist

• Read the contributing guidelines
• Opened this PR as a 'Draft Pull Request' if it is work-in-progress
• Updated the documentation to reflect the code changes
• Added new entries to the RELEASE.md file
• Added tests to cover my changes

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[richardwestenra]

Perfect. Great job! :)