refactor: block editor block for simplicity

[HardeepAsrani]

Summary

This PR:

• Removes legacy block controls from Block Editor: https://docs.themeisle.com/visualizer-charts-and-graphs/how-can-i-display-a-chart#using-visualizer-block
• Removes a lot of code which wasn't being used or was being used but didn't need to be used.
• Switches from the webpack bundling to using wp-scripts for simplicity.

Will affect visual aspect of the product

YES/NO
No

Screenshots

Test instructions

• Make sure the block works properly.
• If it does, we can update the doc here: https://docs.themeisle.com/visualizer-charts-and-graphs/how-can-i-display-a-chart#using-visualizer-block

Check before Pull Request is ready:

• I have written a test and included it in this PR
• I have run all tests and they pass
• The code passes when running the PHP CodeSniffer
• Code meets WordPress Coding Standards for PHP, HTML, CSS and JS
• Security and Sanitization requirements have been followed
• I have assigned a reviewer or two to review this PR (if you're not sure who to assign, we can do this step for you)

Closes https://github.com/Codeinwp/visualizer-pro/issues/561.

[pirate-bot]

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