Zarf config file support using Viper

[jeff-mccoy]

This PR adds support for using Viper to support declarative automation for the Zarf CLI. As more flags are added to Zarf, it can become more imperative at runtime, Viper allows Zarf to remain fully declarative operations supported by automation.

[jeff-mccoy]

So ran into a really interesting thing that I don't think we thought about before... when we bind multiple flags to a single variable, each binding overwrites the default state with the very last binding to it. Ran into this because config.CommonOptions.SetVariables default (which was provided by Viper) was being overridden by the empty default also provided by Viper later on. 🤦

[jeff-mccoy]

Fortunately, the only place we use this that it would actually cause problems is for config.CommonOptions.SetVariables

[jeff-mccoy]

zarf prep gc:

architecture = ''
log_level = 'info'
no_log_file = false
no_progress = false
tmp_dir = ''

[init]
components = ''
storage_class = ''

[init.git]
pull_password = ''
pull_username = ''
push_password = ''
push_username = 'zarf-git-user'
url = ''

[init.registry]
nodeport = 0
pull_password = ''
pull_username = ''
push_password = ''
push_username = 'zarf-push'
secret = ''
url = ''

[package]
[package.create]
insecure = false
output_directory = ''
skip_sbom = false
zarf_cache = '.zarf-image-cache'

[package.create.set]

[package.deploy]
components = ''
insecure = false
sget = ''
shasum = ''

[package.deploy.set]

[Racer159]

lgtm