cat-file: add --batch-command remote-object-info command

Under some circumstances, it is useful to get information about an object without having to download it completely (steaming the data).

The server logic has already been implemented as "a2ba162cda (object-info: support for retrieving object info, 2021-04-20)".

This patch adds client functions to communicate with the server. Specifically, a new remote-object-ino command is added to git cat-file --batch-command.

Currently only size info can be retrieved. A example is like this

• The client user starts command `git cat-file --batch-command"
• The client user type in remote-object-info <remote> <a object SHA>
• The object size is returned without downloading the object on the client

This issue is a prerequisite of git-cat-file: Support for reading objects from a remote without fetching them

This issue is a continuing work effort based on Calvin Wan's v5 patch series