Handle devcontainer pathing

[zendern]

This change will need to also be made in child repos to then use the new functionality of these different paths.

we have several copier templates that have venv/node_modules that are not in the repo root. at some point (not saying now) we should probably move this into copier-base template and make a copier task in the sub-template that just adjusts the paths. the task could be defined in the copier.yaml.jinja-base in the base template, and just read from the envs.json that defines the paths for the different python/node environments in the template

Originally posted by @ejfine in LabAutomationAndScreening/copier-nuxt-python-intranet-app#117 (comment)