feat: Implement bloom_filter_agg

[mbutrovich]

Which issue does this PR close?

Closes #846.

Rationale for this change

What changes are included in this PR?

• Native implementation (bloom_filter_agg.rs) that uses DataFusion's Accumulator trait. We do not have a GroupsAccumulator implementation and leave it as a possible future optimization.
• Serde logic (planner.rs, QueryPlanSerde.scala)
• Serialization and merging logic for underlying data structures (spark_bloom_filter.rs, spark_bit_array.rs)

How are these changes tested?

• New test in CometExecSuite
• Spark tests in CI exercise this aggregation
• Scala benchmark to compare against Spark code path
• Native benchmark for partial and final aggregation modes
• Native tests for new bit array logic spark_bit_array.rs