added fix to the ls command when txtx.yaml file doesn't exist

[0xzrf]

Description

Running surfpool ls on a folder that doesn't have txtx.yaml file in it(or even provided in cli) doesn't output anything

Steps to Reproduce

1. Run surfpool ls on a folder that doesn't have txtx.yaml

Current Behavior

The process exits with a non-zero value, but doesn't log anything that might be helpful to the user

Expected Behavior

The command should:

• Show some error why specifically the command not work

What this PR Solves

This isn't solving a huge problem, but it's still a contribution, as I see it doesn't help the user to know what went wrong. This PR aims to add a simple error handling to the surfpool_cli/src/cli/mod.rs/FN:handle_list_command to show error when something goes wrong while executing the surfpool ls command

[MicaiahReid]

Thanks for the PR, @0xzrf! I changed slightly to more generally improve the error displaying. Will merge once CI runs!