Keyboard navigation support to "plus more" badge for mulitple IPs

[momesgin]

Summary

Fixes #15767

Occurred changes and/or fixed issues

Improved accessibility for the "plus more" badge when there are multiple IPs.

Technical notes summary

• Made the "plus more" selectable by keyboard
• Made the tooltip being visible on focus
• Added aria-label to provide better context

Areas or cases that should be tested

I had to mock multiple IPs scenario, not sure how you can find/create a real case scenario. Once you have the right scenario you should go to Explorer => Cluster => Nodes and then use keyboard to select the "plus more" badge, then hit space/enter key to open the popup, also test using keyboard to apply copy to clipboard and closing the popup.

Areas which could experience regressions

Make sure keyboard navigation is working for the rest of the elements in the table, specially the closest elements to the "plus more"

Screenshot/Video

kn.mov

Checklist

• The PR is linked to an issue and the linked issue has a Milestone, or no issue is needed
• The PR has a Milestone
• The PR template has been filled out
• The PR has been self reviewed
• The PR has a reviewer assigned
• The PR has automated tests or clear instructions for manual tests and the linked issue has appropriate QA labels, or tests are not needed
• The PR has reviewed with UX and tested in light and dark mode, or there are no UX changes
• The PR has been reviewed in terms of Accessibility
• The PR has considered, and if applicable tested with, the three Global Roles Admin, Standard User and User Base

[aalves08]

LGTM