Token limited model context is currently broken because it is importing
from extensions.
This fix removed the imports and updated the model context
implementation to use model client directly.
In the future, the model client's token counting should cache results
from model API to provide accurate counting.
* v1, make assistant agent declarative
* make head tail context declarative
* update and formatting
* update assistant, format updates
* make websurfer declarative
* update formatting
* move declarative docs to advanced section
* remove tools until implemented
* minor updates to termination conditions
* update docs
* make termination condition declarative
* make all term conditions declarative
* make And/OrTermination top level objects in base
* add basic tests
* add tutorial notebook
* update tests and formatting
* update tests
* update declarative config with updated api.
