Ensure DogStatsD source has full data type support.

[tobz]

Context

The DogStatsD source must have full data type support to match what can be accepted in the Datadog Agent and what can be sent by official DogStatsD clients:

• counters
• gauges
• timers
• histograms
• distributions
• sets
• events
• service checks

(Full list, with more detail, here: https://docs.datadoghq.com/developers/dogstatsd/datagram_shell/?tab=metrics#the-dogstatsd-protocol)

In scope

• Decoding DogStatsD payloads with any of the above data types
• Emitting a Metric that faithfully represents those decoded payloads

Out of scope

There's a number of very related items that are out of scope for this particular issue, but will be addressed separately as a follow-up.

• Forwarding all data types to the Datadog platform.

Work items

(non-exhaustive, living list)

• [x] #123
• [x] #124
• [x] #125

[tobz]

This is complete.

This source has full support for all relevant StatsD and DogStatsD data types, and those data types can be faithfully represented within Saluki.