[Feature Request] Fetch templates from configuration first

Expected Behaviour

When running faas-cli up with no template dir, it should fetch templates configured in the stack.yml before fetching official ones.

Current Behaviour

Fetch first from https://github.com/openfaas/templates.git then from configuration.

Why do you need this?

I work with a custom template, shared across projects, so it is hosted on a git repo.
Thus, I need to pull it from my CI/CD in every project.
Currently, if I run faas-cli up it pulls every official template for nothing. It doesn't take a lot of time, but it's wasting network and CI/CD resources.

Are you a GitHub Sponsor

No

Possible Solution

Fetch first configuration and check if all templates used are here before getting the "default" ones.

Workaround

I currently run faas-cli template pull to only pull my template, before running up.
But I would find it more logical if up pull automatically configured templates before default ones.

Your Environment

• FaaS-CLI version: 0.14.6

Start at the faas-cli up entry point and trace how it handles stack.yml template configuration and the default template fetch; compare that flow with faas-cli template pull. Done means configured templates are fetched first and the official templates are skipped when all required templates are available from configuration.