Handle bloom object max allowed size limit, switch fp rate to f64

[KarthikSubbarao]

• Implement a memory / size based limit per filter within a bloom object. This is a new module config: bf.bloom-memory-limit-per-filter.
  • This means every write operation (bloom object creation AND scale outs) that results in a new filter requires the new filter to be within allowed limits. If not, the write request is rejected with an error.
  • Similarly, any RDB Load operation also performs the same memory / size based limit check. RDB Load will fail if any filter within a bloom object has a size larger than what is allowed.
• Switch fp_rate handling through out all occurrences from f32 to f64 to have a higher precision. The main reason for this is during scaling out, every new filter will have a smaller fp_rate (due to the TIGHTENING_RATIO) to maintain the overall fp_rate. We need to handle higher precision fp_rates with every new scale out and f64 handles this better.
• defrag callback was updated to use the new config (bf.bloom-memory-limit-per-filter) to exempt defrag operations when over this limit.

[zackcam]

Just one small nit/question but lgtm!