The PCL binder has supported resource options for some time, but these
options haven't been used or processed by the various code generators.
These options--particularly the parent and provider options0--are
critical for import codegen. These changes implement the basic set of
options, and add a note about fleshing out the rest as necessary.
One component of these changes is a new rewriter that rewrites property
references into property paths that are understood by the Pulumi engine.
This rewriter is used to preprocess the contents of the `ignoreChanges`
resource option.
These changes also hack around a weakness in the HCL2 type system:
In Go, references to resources should be typed as `hcl2.ResourceType`.
Unfortunately, this breaks the existing collection semantics associated
with resources. Because of this, the Go code generator does not have
enough information to know that it should generate a `[]pulumi.Resource`
for lists of resources. These changes hack around that limitation using
a Go-specific opaque type and some hardcoded comparisons in
`argumentTypeName`.
Fixes#4923.
