Move the redirect handling into `git_net_url` for consistency.

Some servers leave the query parameters intact in the
Location header when responding with a redirect.
The service_suffix removal check as written assumed
that the server removed them.
Handle both cases.

Along with PR #5325, this fixes #5321.

There are two new tests. The first already passed;
the second previously failed.

Only read at most INT_MAX from the underlying stream, so that we can
accurately return the number of bytes read.

Since callers are not guaranteed to get as many bytes as requested (due
to availability of input), this is safe and callers should call in a
loop until EOF.

"Connection data" is an imprecise and largely incorrect name; these
structures are actually parsed URLs.  Provide a parser that takes a URL
string and produces a URL structure (if it is valid).

Separate the HTTP redirect handling logic from URL parsing, keeping a
`gitno_connection_data_handle_redirect` whose only job is redirect
handling logic and does not parse URLs itself.

Move to the `git_error` name in the internal API for error-related
functions.

Constant strings and logic for HTTP(S) default ports were starting to be
spread throughout netops.c.  Instead of duplicating this again to
determine if a Host header should include the port, move the default
port constants and logic into an internal method in netops.{c,h}.

RFC 3986 says that hostnames can be percent encoded.  Percent decode
hostnames in our URLs.

Now that we can decode percent-encoded strings as part of `git_buf`s,
use that decoder in `gitno_extract_url_parts`.