µQR: introduce uqr js library, use for QR codes

[systemcrash]

original idea by @Ansuel in #7069
FAO also: @jow- @feckert @hnyman

µQR is ~13K, providing a light-weight option, outputting to only SVG for at least luci-proto-wireguard (example included).
Original library here.

I investigated doing this via ucode RPC calls to avoid a require, but this adds a conversion step from js to ucode, so no go. Depending on the 13K lib is acceptable.

@Ansuel also suggests QR codes for wifi. I could add those also.

Compare: On X86_64 23.05.3, to produce QR codes requires a lib and binary weighing ~ 70K today (>500% bigger).

root@OpenWrt:/# cat /etc/openwrt_release
DISTRIB_ID='OpenWrt'
DISTRIB_RELEASE='23.05.3'
DISTRIB_REVISION='r23809-234f1a2efa'
DISTRIB_TARGET='x86/64'
DISTRIB_ARCH='x86_64'
DISTRIB_DESCRIPTION='OpenWrt 23.05.3 r23809-234f1a2efa'
DISTRIB_TAINTS=''
root@OpenWrt:/# du -h /usr/lib/libqrencode.so* /usr/bin/qrencode
0	/usr/lib/libqrencode.so
0	/usr/lib/libqrencode.so.4
40.0K	/usr/lib/libqrencode.so.4.1.1
28.0K	/usr/bin/qrencode

On ath79 23.05.3, to produce QR codes requires a lib and binary weighing ~ 129K today (~1000% bigger).

root@OpenWrt:~# cat /etc/openwrt_release
DISTRIB_ID='OpenWrt'
DISTRIB_RELEASE='23.05.3'
DISTRIB_REVISION='r23809-234f1a2efa'
DISTRIB_TARGET='ath79/generic'
DISTRIB_ARCH='mips_24kc'
DISTRIB_DESCRIPTION='OpenWrt 23.05.3 r23809-234f1a2efa'
DISTRIB_TAINTS=''
root@OpenWrt:~# du -h /usr/lib/libqrencode.so* /usr/bin/qrencode
0	/usr/lib/libqrencode.so
0	/usr/lib/libqrencode.so.4
64.5K	/usr/lib/libqrencode.so.4.1.1
64.5K	/usr/bin/qrencode

qrencode is a decent tool and can output to a number of formats largely unused on openwrt.

• This PR is not from my main or master branch 💩, but a separate branch ✅
• Each commit has a valid ✒️ Signed-off-by: <[email protected]> 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: (architecture, openwrt version, browser) ✅
• Description: (describe the changes proposed in this PR)

[systemcrash]

If there are no comments on this - esp from @Ansuel - I will merge and liberate wg from qr-encode dep.

[stokito]

The ucr library can be minimized more. I see that it still has things like EccMap={L:LOW,M:MEDIUM,Q:QUARTILE,H:HIGH} that can be inlined to just L. But this is something to discuss with its authors.

[Neustradamus]

@systemcrash: Nice!

@Ansuel: What do you think?

Note: There is Free OTP which is very used on mobile phones (open source not like Google/MS applications):

• https://github.com/freeotp

[stokito]

@systemcrash this was merged