message: add comments on compression
diff: +/*!
  +
  +MultiLinearInterpol compressor uses linear interpolation to guess a values and stores the offset, but in blocks of 512.
  +
  +With a CHUNK_SIZE of 512 and 29 byte metadata per block, we get a overhead for metadata of 232 / 512 = 0,45 bits per element.
  +The additional space required per element in a block is the the maximum deviation of the linear interpolation estimation function.
  +
  +E.g. if the maximum deviation of an element is 12, all elements cost 4bits.
  +
  +Size per block:
  +Num Elements * Maximum Deviation from Interpolation + 29 Byte Metadata
  +
  +*/
  +
  use crate::FastFieldCodecReader;
  use crate::FastFieldCodecSerializer;
  use crate::FastFieldDataAccess;
  