[#49C692A8C61974D65BA4DD42BCD92470A43F9816]
Set the user
static_url& set_encoded_user(pct_string_view s);
This function sets the user part of the userinfo the the string, which may contain percent-escapes. Escapes in the string are preserved, and reserved characters in the string are percent-escaped in the result.
assert( url().set_encoded_user("john%20doe").userinfo() == "john doe" );
this->has_authority() == true && this->has_userinfo() == true
Linear in `this->size() + s.size()`.
Strong guarantee. Calls to allocate may throw.
userinfo = [ [ user ] [ ':' password ] ]
user = *( unreserved / pct-encoded / sub-delims )
password = *( unreserved / pct-encoded / sub-delims / ":" )