feat: #3619736 Use the whole Bootstrap Icons pack for the icon props

Follow-up on #3619736, on top of the merged work.

Badge, Button, Icon and Card Icon still carried a hand-kept enum of icon ids (43, 51, 51 and 43). Bootstrap Icon and Icon Toggle already dropped theirs. This drops the remaining four and keeps x-canvas-icon, so the picker offers the whole Bootstrap Icons pack.

• Removes 384 lines from the manifests.
• Lets Varbase Starter drop 188 allowed_icon_ids entries from its exported config.
• icon_size keeps its enum; those are utility classes, not icon ids.

Existing content stays valid. The Twig guards on icon is not empty and icon != 'none', so stored none values keep rendering.

Verified on Drupal 11.4 with Canvas 1.10.1: the Button picker goes from 51 icons to 2078, rocket (outside the old list) stores and renders, and the shipped pages keep their icons.

Two things to land with it:

• Needs Canvas Icon Picker #3619785. A prop with no allow list silently discards every icon change without it, which already affects Bootstrap Icon and Icon Toggle on this branch.
• Dropping an enum rehashes the component version, so content pinned to the old hash disappears from the Canvas editor until the stored versions are rewritten. Varbase Starter #3619772 carries that migration.

Pipeline run locally with gitlab-ci-local: build, eslint, stylelint and cspell all pass.

This merge request was written with AI assistance, per the Drupal AI policy.

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Remaining tasks

• File an issue about this project
• Addition/Change/Update/Fix to this project
• Testing to ensure no regression
• Automated unit/functional testing coverage — manifest-only change, covered by the existing component discovery and install tests
• Developer Documentation support on feature change/addition — AGENTS.md already documents x-canvas-icon
• User Guide Documentation support on feature change/addition — the picker looks the same, it just offers more icons
• UX/UI designer responsibilities — no visual change
• Accessibility and Readability — no markup change
• Reviewed by a human
• Code review by maintainers
• Full testing and approval
• Credit contributors
• Review with the product owner
• Update Release Notes and Update Helper on new feature change/addition
• Release