generate-manifest-3.5.py: add logic to generate native manifest

generate-manifest-3.5.py: add logic to generate native manifest

python3-native supposes to RPROVIDE all native packages as added in
generate-manifest-3.5.py, but it does not so far, this leads a problem
that sometimes bitbake cant find a runtime provider for a python3-*-native
when a new runtime dependency on it being required, this usualy happens
after a new native python3-* recipe is created or the old native python3-*
recipes are upgraded.

To avoid manually extending RPROVIDE every time when a new runtime
dependency is introduced, an argument '-n/--native' is added to the
manifest generator, allowing it create a native python3 manifest, with a
RPROVIDE line only, the RPROVIDE should contain all the sub-packages.

The generated python-native-3.5-manifest.inc is also added which is
included by python3-native recipe.

(From OE-Core rev: 800753069f667cd1664d70b3779150c467e3b3fe)

Signed-off-by: Ming Liu <peter.x.liu@external.atlascopco.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>