* add model tag to chatCompletion
* add modelTag `model` to async streaming
keeps default arguments for prompt token calculation where applied via explict arg
* fix HF default arg
* render all performance metrics as available for backward compatibility
add `timestamp` to both sync/async chat methods
* extract metrics string to function
* Add className property to various LLM and embedder classes to fix logging bug after minification
* Fix bug with this.log method by applying the missing private field symbol