Resolution result is not consistent with RFC 3986 when the base has "rootless" path without authority

remove_dot_segments defined in RFC 3986 (section 5.2.4) sometimes add a leading slash when the base path is "rootless".

STEP   OUTPUT BUFFER         INPUT BUFFER

 1 :                         foo/../baz
 2E:   foo                   /../baz
 2C:                         /baz
 2E:   /baz

So, resolving ../baz against scheme:foo/bar should result in scheme:/baz.
However, output of this library differs from that.

$ python
Python 3.9.9 (main, Jan 10 2022, 18:52:39)
[GCC 11.2.1 20211127] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from rfc3986 import uri_reference
>>> b = uri_reference('scheme:foo/bar')
>>> r = uri_reference('../baz')
>>> t = r.resolve_with(b)
>>> t
URIReference(scheme='scheme', authority=None, path='baz', query=None, fragment=None)
>>> t.unsplit()
'scheme:baz'
>>>

I think there should be special handling such as "when .. segment appears but output stack is empty, set prepend_slash flag" or something like that.

RFC 3986 のセクション 5.2.4 の規則と、uri_reference、resolve_with、remove_dot_segments のエントリーポイントから始めます。scheme:foo/bar に対して ../baz を解決する例を再現します。既存の解決動作を維持したまま、結果が scheme:/baz に再結合されれば完了です。