`BuildError` response from `wsbuilder` does not support rich errors from validation. Changed this to use the `Validations` block of codersdk responses to return all errors for invalid parameters.
# What does this do?
This does parameter validation for dynamic parameters in `wsbuilder`. All input parameters are validated in `coder/coder` before being sent to terraform.
The heart of this PR is [`ResolveParameters`](b65001e89c/coderd/dynamicparameters/resolver.go (L30-L30)).
# What else changes?
`wsbuilder` now needs to load the terraform files into memory to succeed. This does add a larger memory requirement to workspace builds.
# Future work
- Sort autostart handling workspaces by template version id. So workspaces with the same template version only load the terraform files once from the db, and store them in the cache.
