Get the log of all decisions made on the given conn.

The trace is a list of maps, each map corresponding to one call to a decision function. Each map has the following keys:

• :step: the name of the function that was executed, or the atoms :start or :stop
• :result: the value the function returned
• :timestamp: the time the function was called
• :duration: how long the call took, in native time units

Get a list of tuples for the x-liberator-trace header, based on the given trace.

Log a message containing the given trace, along with its request path and optional request ID.