Leading US manufacturers of medical safety gear told the White House that China prohibited them from exporting their products from the country as the coronavirus pandemic mounted — even as Beijing was trying to “corner the world market” in personal protective equipment, The Post has learned. Now, the Trump administration is weighing legal action against China over its alleged actions, a lawyer for President Trump said Sunday. “In criminal law, compare this to the levels that we have for murder,” said Jenna Ellis, a senior legal adviser to Trump’s re-election campaign.