By Tom Hals WILMINGTON, Del. (Reuters) – Twitter Inc sued Elon Musk on Tuesday for violating his $44 billion deal to buy the social media platform and asked a Delaware court to order the world’s richest person to complete the merger at the agreed $54.20 per Twitter share. “Musk apparently believes that he – unlike every other party subject to Delaware contract law – is free to change his mind, trash the company, disrupt its operations, destroy stockholder value, and walk away,” said the complaint. The lawsuit sets in motion what promises to be one of the biggest legal showdowns in Wall Street …