message: moved more constants out of the duckdb namespace
diff: namespace duckdb {
  +struct UnpackedData {
  + uint8_t leading_zero;
  + uint8_t significant_bits;
  + uint8_t index;
  +};
  +
  +template <class CHIMP_TYPE>
  +struct PackedDataUtils {
  +private:
  static constexpr uint8_t INDEX_BITS_SIZE = 7;
  static constexpr uint8_t LEADING_BITS_SIZE = 3;
  @@ -22,14 +31,6 @@ static constexpr uint8_t LEADING_MASK = ((uint8_t)1 << LEADING_BITS_SIZE) - 1;
  static constexpr uint8_t INDEX_SHIFT_AMOUNT = (sizeof(uint16_t) * 8) - INDEX_BITS_SIZE;
  static constexpr uint8_t LEADING_SHIFT_AMOUNT = INDEX_SHIFT_AMOUNT - LEADING_BITS_SIZE;
  -struct UnpackedData {
  - uint8_t leading_zero;
  - uint8_t significant_bits;
  - uint8_t index;
  -};
  -
  -template <class CHIMP_TYPE>
  -struct PackedDataUtils {
  public:
  //|----------------| //! INITIAL_FILL(16) bits
  // IIIIIII //! Index (7 bits, shifted by 9)
  