GitLab

* tests: add single threaded history test

Also tidies up some existing tests to handle more model output variation

* test: add support for testing specific architectures

usage example:
  go test --tags=integration,perf -count 1 ./integration -v -timeout 1h -run TestModelsPerf 2>&1 | tee int.log
  cat int.log | grep MODEL_PERF_HEADER | cut -f2- -d: > perf.csv
  cat int.log | grep MODEL_PERF_DATA | cut -f2- -d: >> perf.csv

Verified these fail on 0.9.1 and pass on HEAD.

* Move quantization logic to GGML via new backend

This moves the model aware logic to Go code and calls GGMLs quantization code for model creation.

* Remove "add model quantizations"

This is no longer needed now that quantization is implemented in Go+GGML code directly.

Add some new test coverage for various model architectures,
and switch from orca-mini to the small llama model.