0.24: branch.remote doesn't return a Remote object

It seems that the remote property of a branch doesn't return a Remote object. As a consequence it is not possible to query its url property (if any). The only workaround I found was to get the RemoteCollection and filter it to find the remote with the same name as the branch remote_name property.

首先定位 branch.remote 的入口点以及 Remote 和 RemoteCollection 的绑定。将分支的 remote_name 与 RemoteCollection 解析远程仓库的方式进行比较，然后添加一个回归测试，展示 branch.remote 会暴露匹配的 Remote 及其 url 属性。