Convert TypecheckError::Unsafe and TypecheckError::UnsafeFn to errors

[TomAFrench]

noir/compiler/noirc_frontend/src/hir/type_check/errors.rs

Lines 498 to 503 in 6515e4e

	TypeCheckError::Unsafe { span } => {
	Diagnostic::simple_warning(error.to_string(), String::new(), *span)
	}
	TypeCheckError::UnsafeFn { span } => {
	Diagnostic::simple_warning(error.to_string(), String::new(), *span)
	}