introduce CLI command categories to improve help display

[thrau]

Motivation

As the number of CLI commands increases, it becomes harder to separate basic from advanced functionality that is part of our paid offering. This PR introduces the notion of command categories into our localstack command group, that allow us to visually separate the commands.

The current implementation is very rudimentary, with grouping commands manually with a list of commands. I know this is not great, but it's the easiest way to get started without having to introduce additional concepts in ext for now.

Changes

• Rename the ExceptionCmdHandler to a more generic LocalStackCliGroup
• Overwrite the format_commands method of click.Group with our own implementation that adds categories

[coveralls]

coverage: 82.951% (+0.01%) from 82.94% when pulling 7efc2a6 on cli-command-categories into 4d3a8b1 on master.

[github-actions]

LocalStack Community integration with Pro

       2 files         2 suites   1h 18m 0s ⏱️
2 217 tests 1 721 ✔️ 496 💤 0 ❌
2 218 runs  1 721 ✔️ 497 💤 0 ❌

Results for commit 7efc2a6.

[SimonWallner]

LGTM! 🚀

I'm leaning a bit towards a 'running localstack' section with [start, stop, logs, ssh, wait] but we are facing diminishing returns quickly if we have too many sections as already discussed. so happy with it how it is rn.

This change is a good starting point and we should revisit it whenever we add/remove commands. people aint gonna interact with the help every day, so changing it more often, whenever the need arises should not be a issue.

[alexrashed]

I think this is a nice first iteration. I agree that it would be nice to have a way to mark a command as "advanced", but we can look into this once this format has settled. 🚀