…insert operations

This commit introduces a comprehensive Bloom Filter-based conflict detection mechanism
for concurrent merge insert operations in Lance, addressing primary key conflicts
during transaction commits.

Key Features:
- Two-tier storage strategy: exact mapping for small datasets (<200KB), Bloom Filter for large datasets
- Support for multiple primary key types: String, Int64, UInt64, Binary, and composite keys
- Probabilistic conflict detection with configurable false positive rates
- Seamless integration with existing transaction and merge insert workflows

Core Components:
1. Transaction Structure Extension:
   - Extended Transaction protobuf with primary_key_bloom_filter field
   - Added serialization/deserialization support for Bloom Filter data

2. Primary Key Bloom Filter Module:
   - PrimaryKeyBloomFilter wrapper with intelligent storage selection
   - Support for exact mapping (HashMap) and probabilistic filtering (SBBF)
   - Comprehensive primary key type handling and composite key support

3. Conflict Detection Logic:
   - ConflictDetector interface with DefaultConflictDetector implementation
   - Intersection-based conflict detection algorithm
   - False positive identification and graceful handling

4. System Integration:
   - Enhanced TransactionRebase with check_merge_primary_key_conflicts
   - Modified MergeInsertBuilder to collect primary keys during execution
   - Updated Merger struct to track collected primary keys

Technical Specifications:
- Time Complexity: O(k) for insertion and query operations
- Space Complexity: O(m) for Bloom Filter bit array
- Configurable false positive rate (default: 1%)
- Configurable storage threshold (default: 200KB)
- Full backward compatibility with existing Lance functionality

Files Modified:
- protos/transaction.proto: Added primary_key_bloom_filter field
- rust/lance/src/dataset/transaction.rs: Extended Transaction struct
- rust/lance/src/dataset/write/merge_insert.rs: Integrated primary key collection
- rust/lance/src/io/commit/conflict_resolver.rs: Enhanced conflict detection

Files Added:
- rust/lance/src/dataset/conflict_detection/: Complete conflict detection module
  - primary_key_filter.rs: Core Bloom Filter implementation
  - conflict_detector.rs: Conflict detection interface and logic
  - examples.rs: Comprehensive usage examples
  - integration_tests.rs: End-to-end test suite
  - README.md: Module documentation

This implementation provides reliable, efficient concurrent conflict detection
while maintaining Lance's performance characteristics and architectural principles.