Spdb Memtable: use_seek_parralel_threshold mishandled

[Yuval-Ariel]

when running
COMPILE_WITH_UBSAN=1 make -j16 narrow_crash_test

On speedb/v2.5.0

error:
options/options_helper.cc:1128:43: runtime error: load of value 64, which is not a valid value for type 'bool'

cmd to reproduce on empty db:

./db_stress --acquire_snapshot_one_in=0 --allow_concurrent_memtable_write=True --bloom_bits=15.00465222292959 --clear_column_family_one_in=0 --compact_range_one_in=0 --compaction_ttl=0 --compare_full_db_state_snapshot=1 --compression_zstd_max_train_bytes=0 --continuous_verification_interval=0 --customopspercent=5 --db=/tmp/rocksdb_crashtest_narrowjx2xdfdd --delpercent=20 --delrangepercent=0 --destroy_db_initially=0 --enable_compaction_filter=1 --expected_values_dir=/tmp/rocksdb_crashtest_expected_6xt4smoi --fail_if_options_file_error=True --get_current_wal_file_one_in=0 --get_live_files_one_in=50000 --get_sorted_wal_files_one_in=0 --iterpercent=0 --log2_keys_per_lock=1 --max_key_len=8 --memtablerep=speedb.HashSpdRepFactory --mmap_read=0 --nooverwritepercent=50 --ops_per_thread=50000 --partition_filters=0 --periodic_compaction_seconds=0 --prefix_size=-1 --prefixpercent=0 --progress_reports=0 --readpercent=47 --reopen=2 --ribbon_starting_level=0 --secondary_cache_uri= --seed=1134367649 --sst_file_manager_bytes_per_truncate=0 --sync_wal_one_in=25000 --use_direct_io_for_flush_and_compaction=0 --use_direct_reads=0 --use_merge=1 --use_multiget=0 --user_timestamp_size=0 --value_size_mult=8 --verify_db_one_in=50000 --writepercent=28

seems to be caused from RegisterOptions("", &bucket_count_, &hash_spd_factory_info);
since hash_spd_factory_info also contains use_seek_parralel_threshold which is of OptionType::kBoolean

already pushed to the branch where the fixes need to happen