Fix default constructor of bit vector (size was not initialized)

Author: kurpicz

include/pasta/bit_vector/bit_vector.hpp

@@ -209,13 +209,13 @@ class BitVector {
 
 private:
   //! Size of the bit vector in bits.
-  size_t bit_size_;
+  size_t bit_size_ = 0;
   //! Size of the underlying data used to store the bits.
-  size_t size_;
+  size_t size_ = 0;
   //! Array of 64-bit words used to store the content of the bit vector.
   tlx::SimpleVector<RawDataType, tlx::SimpleVectorMode::NoInitNoDestroy> data_;
   //! Pointer to the raw data of the bit vector.
-  RawDataPointer raw_data_;
+  RawDataPointer raw_data_ = nullptr;
 
 public:
   /*!