add end-2-end tests for modules

[matifali]

• Test coder_parameter with and without default
• Test all example cases
• Test coder_script based modules
• Test if coder_apps are healthy and accessible.

We can have a test deployment for testing modules and use ci to create and update templates using modules and test using a workspace.

[bpmct]

I don't have strong opinions on whether we should e2e test our modules versus. I think e2e testing our example templates is a good way to avoid bugs in our most critical modules and then #55 can at least ensure that a template isn't randomly updated to a module that is broken.