The City of Boston’s lawsuit challenging the validity of a license awarded for a casino in Everett returns to court on Tuesday afternoon, when a Superior Court judge is expected to consider whether to allow the legal challenge to go forward. Under an aggressive legal strategy pursued by Mayor Martin J. Walsh, the City of Boston has filed hundreds of pages of legal documents in its claim that the state Gaming Commission’s award last year of a coveted casino license to Wynn Resorts was “the product of a corrupt process.”