MOLD does not handle correctly URLs containing encoded characters

[rebolbot]

Submitted by: Ladislav

As it looks, MOLD does not "expect" to encounter encoded characters in URLs. That is not a correct behaviour, since the characters are encoded when they are not meant as delimiters.

mold #[url! "http://a.b.c/d?e=f%26&g=h"]
; == "http://a.b.c/d?e=f%2526&g=h"
; "http://a.b.c/d?e=f%26&g=h" expected!

^{CC - Data [ Version: r3 master Type: Bug Platform: All Category: Datatype Reproduce: Always Fixed-in:none ]}

[rebolbot]

Submitted by: BrianH

This is related to #1327, #1333 and #1644.