test(accordion): migrate tests to Playwright

[averyjohnston]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
  • Some docs updates need to be made in the ionic-docs repo, in a separate PR. See the contributing guide for details.
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe): Playwright migration

What is the current behavior?

Tests are written in Puppeteer.

Issue URL: N/A

What is the new behavior?

Tests migrated to Playwright.

Redundant tests removed:

• Anything RTL-specific
• A11y screenshot test (covered by Basic test)
• Mode-specific accordions in Basic test
• Multiple-selection accordion in Basic test (covered by Multiple test)

Also added values to accordions in the Basic test so inset styling is actually captured.

Does this introduce a breaking change?

• Yes
• No

Other information

[liamdebeasi]

Some screenshots appear to be cut off at the bottom:

core/src/components/accordion/test/standalone/accordion.e2e.ts-snapshots/accordion-standalone-ios-ltr-Mobile-Safari-linux.png
core/src/components/accordion/test/standalone/accordion.e2e.ts-snapshots/accordion-standalone-ios-rtl-Mobile-Safari-linux.png
core/src/components/accordion/test/standalone/accordion.e2e.ts-snapshots/accordion-standalone-md-ltr-Mobile-Safari-linux.png
core/src/components/accordion/test/standalone/accordion.e2e.ts-snapshots/accordion-standalone-md-rtl-Mobile-Safari-linux.png

[sean-perkins]

Nice work!