Provide a textual based terminal user interface for the command centre

[devraj]

A completely unnecessary but cool request but following from #13 working so nicely and @Textualize offering cool libraries like trogon and textual I thought would't it be nice to provide an additional terminal based interface which isn't exactly a CLI but not a traditional GUI.

Moreover this will extend out Python skills on the CLI and allow us to value add the library.

The why of this request really is around bringing richer CLI tools for the Gallagher ecosystem.

Note that this request and the CLI should be additional poetry installables. The API client should be a product of its own.