Add a behat scenario ensuring a Rows object stays valid after fetching next page

Adding DSE graph data type test and minor refactoring

…erators (log datastax#11)

- Added CASS_ITERATOR_TYPE_VECTOR to allowed types in cass_iterator_get_value()
- This was causing iterator to return NULL elements even though decoding was correct
- Float vector round-trip test now passes successfully
- Fixed-length vector elements (float, int) now work properly

- Implement strict type checking for vector binding in prepared statements
- Parse VectorType from CustomType class name to validate element type and dimension
- Ensure both element type and dimension match exactly
- Prevents dangerous type mismatches (e.g., int vector in float column)
- All 17 integration tests passing with Cassandra 5.0.5

This is a critical fix for data integrity when using vectors with prepared statements.

…(log datastax#11)

- Created comprehensive test suite for ALL 19+ vector types
- Verified C++ <-> Go driver interoperability with bidirectional tests
- Both simple and prepared statements working for all types
- Round-trip verification implemented and passing
- Fixed query issues (removed unnecessary frozen, using keyspace prefixes)
- All primitive types tested: numeric, string, boolean, UUID, blob, timestamp, etc.
- Complex types (collections in vectors) partially working (API additions needed)

…(log datastax#11)

- Modified cass_vector.hpp to bypass type validation for "unknown" element types
- Updated decoder.cpp to handle "unknown" types with collection heuristics
- Added cass_vector_element_data_type() API for type introspection
- Created comprehensive integration tests for complex vector types

This implementation allows complex vectors (vector<list<int>>, vector<set<text>>, etc.)
to work with prepared statements despite receiving "unknown" type metadata from server.
Server-side validation ensures data integrity.

Key findings:
- C++ driver receives "unknown" for complex element types
- Go driver v2 receives full type information for same queries
- Both drivers use protocol v4, so not a protocol issue
- Write path works correctly, read path has iterator limitations
- Non-frozen collections work better for driver interoperability

Next: Investigate root cause of type metadata discrepancy between drivers