Support .tf files created by other bazel targets

[ggramal]

There are some cases in which we would like to use .tf files after they are processed by other targets. For example setting tf backend attributes programmatically which is impossible to do using tf vars.

By design for build rules like init,plan, those files are placed under bazel-out/cpu-compilation_mode/bin In order to use those .tf files we need to copy them inside execpath