feat(useMouse): support custom event extractor

[RAX7]

Add target option and type enhancement

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⚠️ Slowing down new functions

Warning: Slowing down new functions

As the VueUse audience continues to grow, we have been inundated with an overwhelming number of feature requests and pull requests. As a result, maintaining the project has become increasingly challenging and has stretched our capacity to its limits. As such, in the near future, we may need to slow down our acceptance of new features and prioritize the stability and quality of existing functions. Please note that new features for VueUse may not be accepted at this time. If you have any new ideas, we suggest that you first incorporate them into your own codebase, iterate on them to suit your needs, and assess their generalizability. If you strongly believe that your ideas are beneficial to the community, you may submit a pull request along with your use cases, and we would be happy to review and discuss them. Thank you for your understanding.

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Description

• Added a new target option to listen for events only on the target element and not on window. It's helpful for performance improvement to do not triggers refs update then you not need it. Also it's allows to use some event properties which relative to target element (e.g. event.offsetX)
• Allows the type option to be used as a function that retrieves the x and y values from the event object. If the function returns null | undefined refs will not be updated.

Additional context

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🤖 Generated by Copilot at 0d9e2ac

Enhanced useMouse function to support custom elements and coordinate extractors. Updated demo, types, and documentation accordingly.

🤖 Generated by Copilot at 0d9e2ac

• Add and document target and type options to useMouse function (link, link, link)
• The target option allows specifying a custom element to listen to mouse events, using a direct value or a function that returns a value (link, link, link)
• The type option allows providing a custom function to extract the mouse coordinates from the event, or choosing from predefined coordinate systems (link, link, link, link, link)
• Refactor and simplify event handlers and listeners in useMouse function (link, link)
  • Use the extractor variable to store the function that gets the mouse coordinates from the event, either from the type option or from the EXTRACTORS object (link, link)
  • Update the x, y, and sourceType refs with the mouse coordinates and the event source (link, link)
  • Use the eventFilter option if provided, or directly call the handler functions otherwise (link)
  • Use the target parameter instead of the window object for the useEventListener hooks (link)
• Update the demo.vue file to show the usage of the new target and type options (link)
  • Show the difference between the default usage and the usage with an extractor function that only returns the offset coordinates of the mouse relative to the parent element (link)