started design doc about SQM model, building and translation;
initial work on `#load` support (strange error in BasicFormatterImpl as part of SqlStatementLogger)
- Continued work on mapping model and conversion from SQM to SQL. Currently flushing out mapping model - how expressive do we want this to be? Do we really want to re-use the walking contracts? Or create a new SPI/impls based on MappingModelExpressable?