Bazel to CMake: Refactor _convert_target()
Bazel to CMake: Refactor _convert_target()

* Don't add full package name to local deps
* Handles local deps and IREE deps including the full package name within the same conversion block
* Drop local deps ending on `_gen` or `Gen`

Closes https://github.com/google/iree/pull/622

COPYBARA_INTEGRATE_REVIEW=https://github.com/google/iree/pull/622 from iml130:bazel-to-cmake-2 06f207eecff645af076bd359eec114dfe8adb029
PiperOrigin-RevId: 292386664

iree-org/iree,google/iree,google/iree,google/iree,google/iree,iree-org/iree,google/iree,iree-org/iree,iree-org/iree,iree-org/iree,google/iree,iree-org/iree,iree-org/iree,google/iree