feat(buttons): add tooltip support to selection buttons

[dauriamarco]

Adds tooltip support to selection buttons so that they can support tooltips in all configurations both when the label wraps the input/element (text, icon, etc.) and when there’s no wrapping label (using the for attribute).

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[gemini-code-assist]

Code Review

This pull request adds tooltip support for selection buttons by overlaying the native input element on top of the styled label. This is a good approach to leverage native browser tooltip behavior. The changes in the SCSS files correctly implement this for cases where the input is wrapped within the label. However, there is an issue with the implementation for sibling input/label elements, where a fixed-width overlay is used, which doesn't work for buttons with variable-width text. I've added a comment with details on this. The changes to the example page and e2e tests are consistent with the new approach.

[github-actions]

Documentation.
Examples.
Playwright report.

Coverage Reports:

• element-ng
• element-translate-ng

[spliffone]

Can we please add a test case to verify the behaviour, wither vrt or jasmine?

[github-actions]