luci-base: expose static IPv6 configuration even if IPv6-PD is enabled.

[adelton]

• This PR is not from my main or master branch 💩, but a separate branch ✅
• Each commit has a valid ✒️ Signed-off-by: <my@email.address> row (via git commit --signoff)
• Each commit and PR title has a valid 📝 <package name>: title first line subject for packages
• Incremented 🆙 any PKG_VERSION in the Makefile
• Tested on: x86_64 VM with OpenWrt 24.10.0-rc5 (r28304-6dacba30a7)
• ( Preferred ) Mention: @ the original code author for feedback
• ( Preferred ) Screenshot or mp4 of changes:
• ( Optional ) Closes Interface IPv6 configuration: PD and static IPv6 address #3340
• ( Optional ) Depends on: e.g. openwrt/packages#pr-number in sister repo
• Description: expose static IPv6 configuration even if IPv6-PD is enabled.

[adelton]

I had to move this PR one commit back in the master branch, to avoid the issue being addressed by #7557.

[Ramon00]

Would this not make it confusing for most people? I.e. nowhere is it now shown that this is optional if you have IPv6-PD?

[adelton]

Well the values are optional since they are not mandatory. :-)

What is your suggestion? Do you think we should add some explicit hints about these being optional and "possibly not needed" when IPv6-PD is enabled? Or?

[Ramon00]

yeah maybe add to the hint "optional if IPv6-PD enabled". Alternative would be add an extra toggle "enable manual IPv6" which only shows up if you have IPv6-PD and which unhides the additional 3 items?