Function align_to_byte 

fn align_to_byte<F>(buffer: &mut [u8], op: &mut F, offset_in_bits: usize)
where
    F: FnMut(u64) -> u64,

Align to byte boundary by applying operation to bits before the next byte boundary.

This function handles non-byte-aligned operations by processing bits from the current position up to the next byte boundary, while preserving all other bits in the byte.

Arguments

• op - Unary operation to apply
• buffer - The mutable buffer to modify
• offset_in_bits - Starting bit offset (not byte-aligned)