fix(core/dropdown): fix runtime & detach issues

[matthiashader]

💡 What is the current behavior?

• When detaching and attaching the ix-dropdown inside the DOM, the dropdown stop working, it is not possible to actually open the dropdown again
• When in the runtime a element is added to the DOM, with the ID 'undefined' the trigger wil be set to this element and not longer be available on the button / select and so on.

GitHub Issue Number: #1136

🆕 What is the new behavior?

• When the dropdown is attached again to the DOM the listeners are initialised again
• When a new element with ID 'undefined' is added, a condition will prevent the element from actually setting it as trigger element

🏁 Checklist

A pull request can only be merged if all of these conditions are met (where applicable):

• 🦮 Accessibility (a11y) features were implemented
• 🗺️ Internationalization (i18n) - no hard coded strings
• 📲 Responsiveness - components handle viewport changes and content overflow gracefully
• 📄 Documentation was reviewed/updated (pnpm run docs)
• 🧪 Unit tests were added/updated and pass (pnpm test)
• 📸 Visual regression tests were added/updated and pass (Guide)
• 🧐 Static code analysis passes (pnpm lint)
• 🏗️ Successful compilation (pnpm build, changes pushed)

👨‍💻 Help & support

[changeset-bot]

🦋 Changeset detected

Latest commit: 9f32b7c

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 4 packages

Name	Type
@siemens/ix	Patch
@siemens/ix-angular	Patch
@siemens/ix-react	Patch
@siemens/ix-vue	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR