Query Statistics and Tracing

[lbeurerkellner]

We want to enable more insight into the internals of LMQL by providing a simple interface for users to log and trace LMQL execution on a per-query basis. In this issue, we want to investigate and collect the different types of data users may want to collect during execution. For a first version, we want to consider the following:

• Logging API/token use per query call

• Logging all API requests with prompts and parameters that are sent out as part of query execution

• Aggregate of all queries run in a specific context (for programs that run multiple queries)