Add standard value sources to nyc_taxis to allow using range query randomization

[peteralfonsi]

Description

opensearch-project/opensearch-benchmark#455 introduced logic to controllably randomize range queries, which is useful for testing caching behavior. This requires registering "standard value sources" for each operation, which produce a random gte/lte value for the query.

This PR adds these for nyc_taxis, so you don't have to use a custom version of the workload in your own fork. These standard value sources have no effect if the flag --randomization-enabled isn't used. (See the randomizer code).

This PR is a first step towards adding a nightly benchmark using randomization. This will help us catch cache-related performance issues.

Tested with randomization both on and off, and saw no errors.
Randomization on:
opensearch-benchmark execute-test --pipeline=benchmark-only --workload-path=/home/ec2-user/osb/opensearch-benchmark-workloads/nyc_taxis --workload-params='{"requests_cache_enabled":"true"}' --target-host=http://localhost:9200 --randomization-enabled --randomization-repeat-frequency 0.3 --randomization-n 10000 --randomization-alpha 0.9 --throughput-percentiles 0,25,50,75,100 --latency-percentiles 0,10,20,25,30,40,50,60,70,75,80,90,99,99.9,99.99,100 --test-mode

Randomization off:
opensearch-benchmark execute-test --pipeline=benchmark-only --workload-path=/home/ec2-user/osb/opensearch-benchmark-workloads/nyc_taxis --target-host=http://localhost:9200 --throughput-percentiles 0,25,50,75,100 --latency-percentiles 0,10,20,25,30,40,50,60,70,75,80,90,99,99.9,99.99,100 --test-mode

Issues Resolved

N/A

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[IanHoang]

This is clean. Thanks for contributing this!