SNOW-1452696: Add a method for using `env` variables in arbitrary commands

[sfc-gh-zblackwood]

Description

For example, if I put

env:
    - role: foo

Then I should be able to do snow streamlit deploy --role env.role or something similar

This is already possible via yq, but it's a bit of a pain

yq eval '.streamlit.env.role' snowflake.yml

Context

We can already use these variables for snow sql commands using jinja syntax, but it would be more helpful if we could do it for other snow commands.

The way to pull this