Provide a "tui" option

Problem to solve

As a developer, I want to be able to get a better general view of the current status of the project in a similar way to what users get with GitLab Workflow on Visual Studio Code.

Proposal

I propose a terminal user interface that is capable of showing issues, merge requests, wikis and allow the user to navigate through them. It could be called with glab without parameters.

Links / references

There are tools that provides the same experience like lazygit and lazydocker among a vast list of tui tools.