fix(lambda-tiler): correctly log fetch requests

[blacha]

Motivation

Requests tracing has been broken for a while (not entire sure when it broke)

It is very very helpful to have statistics on the number of s3 requests required to make a tile

Modifications

• requestCount is reserved for the number of lambda invocations so move to fetchCount for number of fetches
• include the fetchIds to trace hot fetches
• increase the percent of requests with tracing enabled
• Use async local storage to gain access to the logger for the request that triggers the log message, this fixes a bug where the request may be in trace but the fetch is using the base logger which is set to info so no logs are generated.

Verification

Ran locally and verified logs are now appearing.