[KED-2381] Refactor zoom and views

[bru5]

Description

Abstracts and improves the viewport implementation.
This follows up recent view work from #356.

Development notes

• moves viewport code into a separate view utility
• this simplifies and unifies the flowchart and minimap components
• provides a more consistent and convenient API for this usage
• improves test coverage throughout

QA notes

Behaviour should not change.

All flowchart and minimap functionality involving view effects should be tested.

Refer to notes in #356 for rules on how the view should now act.

This will include testing in various combinations:

• open / closed sidebar and metadata panel
• resizing the browser to various viewport sizes / aspect ratios
• different graph aspect ratios (square, wide, tall)
• selecting elements on the sidebar and on the chart
• selecting tags and pipelines
• toggling labels
• using the minimap

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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[studioswong]

Just tested and played around with the new zoom views and they work well, really great stuff @bru5 ! 👍

one thing with regards to structuring of the tests - given the code is highly specialised with different formulas / calculations to cater for the different zoom scenerios that was outlined in the QA section, the cases outlined in the tests would be quite crucial in helping the user understand the different functions and how it caters for the different use case. I understand they are structured as unit tests, could you please add some tests cases to outline the different scenerios you listed in the QA ( or if some unit tests covers that, you can also mention that in the test description?)

Thank you!