fix(paginator): fix focus management to properly account for state updates while the element is already focused

[DRiFTy17]

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added/updated: Y
• Docs have been added/updated: N
• Does this PR introduce a breaking change? N
• I have linked any related GitHub issues to be closed when this PR is merged? N

Describe the new behavior?

The paginator will now manage its internal focus state in the following scenarios:

1. When state is updated that causes a button to get disabled, but only while the element is focused
2. In response to user interaction with one of the buttons that causes the button to be disabled upon clicking (again only while the field already has focus)
3. In response to a user interaction, but the state is changed from the change event listener. This is the same as the first scenario, but the order of operations is different (and this is a common use case that we now test for)

The goal is to now ensure that we only move focus from the component if it already has focus at that time. This ensures that we allow for both user actions and programmatic state changes to move focus the same way, but it's more clear when this can happen now.

Additionally, a new focus() override method was provided that allows for programmatically focusing the paginator element because this was missing functionality before, and is standard for interactive HTML elements.

Additional information

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🚀 PR was released in v3.0.0-next.13 🚀