Implement crosstest.Update (PF)

[iwahbe]

A pre-requisite for #2843, we should implement crosstest.Update for PF. The test function will have the signature:

package crosstest

// Update will assert that a provider will observe the same inputs when transitioning a
// resource described by schema from initialState to finalState.
//
// Update is safe to run in parallel.
func Update(t T, schema pschema.Schema, initialState, finalState map[string]cty.Value, options ...UpdateOption)

The test should be added in the newly created github.com/pulumi/pulumi-terraform-bridge/pkg/pf/tests/internal/cross-tests/update.go file.

Configure is a useful example for what this kind of cross-test looks like.