update hx-live to use xpath and handle alpine conflict

[MichaelWest22]

Description

hx-live should use xpath for more efficient scanning of hx-live:* attributes as it currently does inefficient full scans.

Also need to address the alpine compatibility issue. Alpine uses the same :attr form as the proposed hx-live parsing and if they are both enabled then they both try and register the same behavior and the different syntaxes causes errors. While we could move to a safer default short bind form like live:attr or hx:attr or _attr none of them are as nice and well understood as the alpine pattern. So to avoid conflicts we could detect alpine and disable the default : short form prefix and post a warning to the console so users can opt in or out of the short form or pick an alternative short form.

Corresponding issue:

Testing

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Checklist

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