Function base64_url::escape_u8_slice_in_place

pub fn escape_u8_slice_in_place<S: ?Sized + AsMut<[u8]>>(
    base64: &mut S
) -> &[u8]

In-place escape Base64 data to Base64-URL data. The conversion is not concerning with Base64 decoding. You need to make sure the input Base64 data is correct by yourself.