Benchmark `Trace.cpp:SuppressionMap`

`Trace.cpp:SuppressionMap` would (1) create a copy of the `TraceEvent` `type` string (2) Store the string inside the `std::map` data structure.

Considering the frequency of using `TraceEvent` it might be interesting to see:

1. It is possible that `SuppressionMap` will only create a copy of the `TraceEvent::type` when it is unknown.
2. Try `std::unordered_map` or some other custom implementation?

Start at Trace.cpp:SuppressionMap and inspect how TraceEvent::type is copied and stored. Benchmark the current std::map behavior against avoiding copies for known values and the proposed std::unordered_map or custom implementation. Done means the alternatives have comparable results and a justified implementation choice.

Written by the indexing model from the issue text.