CLI needs to use venvs appropriately #367
Description
Describe the solution you'd like
The CLI needs to create and install ComfyUI deps inside a venv, and subsequently start that venv when a user launches Comfy with the CLI.
Describe alternatives you've considered
The only solution to not nuking your system Python is to counter-intuitively install the CLI within a venv, even though a CLI tool should be globally available outside a venv. However, the reality is that the install, update, and launching functionality of the CLI might be better served if it is moved to the main repo as a bash script (I have built such a script if interested) for general ease of installing, maintaining, and launching.
Additional context
This is to reduce the amount of people who install Comfy either manually or through the CLI from nuking their system python by polluting it with a ton of unnecessary and conflicting dependency additions/changes, which is a common pain point among many.