feat: add list view toggle to chart library with user meta persistence

[HardeepAsrani]

Summary

Adds a grid/list view toggle to the Visualizer library page. List view renders charts in a WP-style table. The selected view is saved to user meta so it persists across visits without a redirect.

• List view: WP table layout, no canvas rendering, tooltips on actions
• Shortcode cell is clickable to copy to clipboard with visual feedback
• View preference saved via update_user_meta() with allowlist validation
• 10 Playwright e2e tests covering toggle, persistence, and table content

Will affect visual aspect of the product

YES

Screenshots

Test instructions

• Make sure the List/Grid layouts both work properly.
• Make sure the change of layouts is persistent.

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/510.

[pirate-bot]

Plugin build for 0010c70 is ready 🛎️!

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[rodica-andronache]

@HardeepAsrani

• Can we move the notice at the top? Right now, not sure why, it appears after two charts like this

• The download PNG is missing from the List view. Can it be added?

• For the Edit button, can we add the "Edit" text with the little crayon icon instead of the wheel?

[HardeepAsrani]

The download PNG is missing from the List view. Can it be added?

No, we can't. The chart needs to be rendered for us to screenshot it.

[rodica-andronache]

@HardeepAsrani I can't see the changes. The notice is still at the bottom in List view

now, the previous notice is back in Grid mode

the Edit button is the same.

I'm missing something?

[HardeepAsrani]

@rodica-andronache No, it was my fault. Should be fine now.

[rodica-andronache]

@HardeepAsrani thanks! The notice should be the same in both views.
How it's now in list view

It should be in Grid too. I see the old one

Also, can we add the "Edit" text to the Edit button?