[AIP-87][Discussion]Introduce native API to evaluate aggregator value is greater or equal to given amount

[thepomeranian]

AIP Discussion

Calling aggregator_v2::is_at_least API, returns true if aggregator value is larger than or equal to the given min_amount, false otherwise.

Aggregators are concurrent counters, allowing for modification without introducing read/write conflicts. Revealing the actual value (read) introduces the read-write conflict back, but in cases where we need to reveal a property on the value - that can be done so efficiently and in a parallel friendly way, via existing branch prediction. And so this operation is more efficient and much more parallelization friendly than calling read(agg) > min_amount.

Read more about it here: https://github.com/aptos-foundation/AIPs/blob/main/aips/aip-87.md