Feat/hx reselect support unset

[oliverhaas]

Description

HX-Reselect currently does not support unset like the attribute hx-select does. I think an htmx user would expect that, and for me it is quite handy to have that feature.

I hope it is okay for me to open a PR to illustrate the linked issue, since it's somewhere in-between a feature and a bugfix I would say.

Corresponding issue: #3152

Testing

Basically already using this in one of my projects to have server-side rendering of redirects.

If the server would trigger a redirect, I just render the response of the redirected view and use HX-Reselect, HX-Retarget, HX-Reswap for swapping. Saves me one round trip and let's me use redirects more freely. And for full body swaps I need to use unset.

Checklist

• I have read the contribution guidelines
• I have targeted this PR against the correct branch (master for website changes, dev for
  source changes)
• This is either a bugfix, a documentation update, or a new feature that has been explicitly
  approved via an issue
• I ran the test suite locally (npm run test) and verified that it succeeded

[Telroshan]

Yeah, makes sense to me to have the header replicate the attribute's potential values, including unset

[scrhartley]

I'd like to express my support of this since it will also allow htmx:beforeSwap to use unset as the value for selectOverride.

[oliverhaas]

In case I'm missing something I have to do to get this merged, please tell me. I'd like to think I'm "experienced" by now, but a lot is still new to me :).

[scrhartley]

In case I'm missing something I have to do to get this merged, please tell me. I'd like to think I'm "experienced" by now, but a lot is still new to me :).

Don't worry, just continue to be patient. The "ready for review" label means you're doing well.

[1cg]

@oliverhaas nothing on you, i'm just old, busy, tired and extremely lazy.

thanks for your contribution