Add Lexbor files for URL handling

[kocsismate]

Relates to #14461 and https://wiki.php.net/rfc/url_parsing_api

[nielsdos]

The build failure seems legit, the definition is missing a field:

{0, LXB_UNICODE_QUICK__UNDEF, 0, 0, 0},

Although legal, our build system is more strict. It should be fixed in upstream. I'll get that sorted: lexbor/lexbor#280

[kocsismate]

The build failure seems legit, the definition is missing a field:

Thanks for the investigation! I was about to ask whether I can suppress the error or not (and actually, I've just pushed the suppress). But then I'll wait for the fix

[TimWolla]

For visibility, officially requesting changes for lxb_url_serialize_unicode(). It should either be upstreamed or added to the patch files.

[kocsismate]

For visibility, officially requesting changes for lxb_url_serialize_unicode(). It should either be upstreamed or added to the patch files.

I temporarily got rid of the custom code inside lexbor so that this PR could be merged immediately (and I can continue working on the next PR containing the WHATWG API).

[TimWolla]

Verified that the files match lexbor/lexbor@506ae05. For the config.m4 / config.w32 changes I trust that you tested them.

[kocsismate]

Rebased the PR on top of current master (so that ext/uri related changes are there) + added a very small change (alphabetical ordering fix)

[TimWolla]

Confirmed that the ext/lexbor/lexbor files are unmodified since my last approval.