feat: render global environment outside tutor-env

[mariajgrimaldi]

Description

This PR adds a new manifest builder that generates manifests outside the usual tutor environment, which are meant to be used to create global resources for a cluster.

How to test

Generate a drydock environment using a reference with the GlobalManifests builder, e.g:

drydock:
  builder_class:  drydock.manifest_builder.application.manifest_builder.ManifestBuilder
  config_class: drydock.manifest_builder.infrastructure.tutor_config.TutorExtendedConfig
  manifest_class: drydock.manifest_builder.infrastructure.tutor_based_manifests.GlobalManifests
  manifest_options:
    output: "global-env"

After running tutor drydock save -r drydock-reference.yml, a new env called global-env will be generated with the customization file rendered

[MoisesGSalas]

I'm thinking of not using default here and instead having them in the defaults.yml file? That way we can refer to that file to know what variables are available.

[mariajgrimaldi]

Done! :)

[mariajgrimaldi]

hey! what do you think now? @jfavellar90 @MoisesGSalas