Moving the transformer wholesale looks like it broke some tests, with
some actually doing legit work in normalizing singular resources from a
foo.0 notation to just foo.
Adjusted the TestPlanGraphBuilder to account for the extra
meta.count-boundary nodes in the graph output now, as well as added
another context test that tests this case. It appears the issue happens
during validate, as this is where the state can be altered to a broken
state if things are not properly transformed in the plan graph.
This fixes interpolation issues on grandchild data sources that have
multiple instances (ie: counts). For example, baz depends on bar, which
depends on foo.
In this instance, after an initial TF run is done and state is saved,
the next refresh/plan is not properly transformed, and instead of the
graph/state coming through as data.x.bar.0, it comes through as
data.x.bar. This breaks interpolations that rely on splat operators -
ie: data.x.bar.*.out.
This adds a unit test to the test provider that verifies count.index
behaves correctly. Although not ideal this is hard to implement as a
context test without changing around the (non helper/schema)
implementation of the x_data_source.