By Sabine SieboldWIESBADEN, Germany (Reuters) -Ukraine will let foreign arms companies test out their latest weapons on the front line of its war against Russia's invasion, Kyiv's state-backed arms investment and procurement group Brave1 said on Thursday.Under the "Test in Ukraine" scheme, companies would send their products to Ukraine, give some online training on how to use them, then wait for Ukrainian forces to try them out and send back reports, the group said in a statement."It gives us understanding ...