[Feat] Provide GraphAr command line interface

**Is your feature request related to a problem? Please describe.**
The GraphAr CLI could be provided as a convenient interactive command to look up and manage the graph data stored in GraphAr in an intuitive manner.

**Describe the solution you'd like**
The GraphAr CLI would enable the users to easily list their graph instances, look up their metadata in the most intuitive manner. Also CLI provides useful commands to easily interact with the data stored on GraphAr, such as to count the number of chunks, total size and so on.
In addition to that, the GraphAr CLI could offer the ability to customize the user interface to display relevant help messages and provide quick access to all the related commands.

**Describe alternatives you've considered**
A clear and concise description of any alternative solutions or features you've considered.

**Additional context**
Add any other context or screenshots about the feature request here.

No implementation files, tests, or entry points are named in the issue; start by surveying the repository's existing interfaces and build/test layout to locate the CLI entry point. Define the command scope and verify that it can list graph instances, show metadata, count chunks, report total size, and provide help and customization before considering the feature done.

Written by the indexing model from the issue text.