new for Block<S>

[OmmyZhang]

It's necessary to create an empty Block<Complex> sometimes, to avoid incompatible types. But now Block::new can only create an empty Block<Simple>

clickhouse-rs/src/types/block/mod.rs

Lines 140 to 144 in 84a35d5

	impl Block {
	/// Constructs a new, empty `Block`.
	pub fn new() -> Self {
	Self::with_capacity(DEFAULT_CAPACITY)
	}

[OmmyZhang]

Block<Complex>::default() works, but moving new and with_capacity from impl Block(which means Block<Simple>) to impl<K: ColumnType> Block<K> may be better?