WASHINGTON — Former President Donald Trump proposed Thursday that in-vitro fertilization (IVF) be made free for wannabe parents — a sweeping pitch that could transfer as much as $7 billion in annual costs to the government and insurance companies, experts tell The Post. The Trump team hasn’t specified how the policy would be adopted, but the quickest way is likely through pending legislation requiring insurance companies to consider infertility a covered medical condition or through amending former President Barack Obama’s signature 2010 healthcare law. If Trump, 78, manages to become…