Collect match failure statistics from Reporter instances

[drewda]

Each Reporter instance now logs statistics on match failures (see opentraffic/reporter#34). We should aggregate this at the Datastore for debugging and evaluation purposes.

An option to consider:

• send from Reporter to an S3 bucket (either directly or through Kinesis Firehose)
• store in structured files in S3 (likely CSV or JSON)
• whenever it's necessary to run queries on the stats, load the files from S3 into AWS Athena

We should also consider any privacy-related concerns around the statistics being aggregated.