perf(cli): speed up

[aarnphm]

This PR speeds up CLI performance by 100ms

Tested with hyperfine with 3 rounds of warmup and 1000 runs.

This PR also refactor some of the utilities functions that is only used by bentoml_cli
to bentoml_cli folder, which also helps with import speeds

This PR also add a regression tests to make sure that in the future, if we accidentally
introduce a heavy imports, we will be able to catch it.

[codecov]

Codecov Report

Merging #2934 (8f4a117) into main (901256c) will increase coverage by 0.89%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #2934      +/-   ##
==========================================
+ Coverage   69.88%   70.78%   +0.89%     
==========================================
  Files         121      104      -17     
  Lines        9961     9473     -488     
==========================================
- Hits         6961     6705     -256     
+ Misses       3000     2768     -232     

Impacted Files	Coverage Δ
bentoml/_internal/frameworks/torchscript.py	0.00% <0.00%> (-95.92%)	⬇️
bentoml/_internal/frameworks/common/pytorch.py	0.00% <0.00%> (-72.64%)	⬇️
bentoml/_internal/runner/strategy.py	83.05% <0.00%> (-8.48%)	⬇️
bentoml/_internal/runner/runner_handle/local.py	76.00% <0.00%> (-8.00%)	⬇️
bentoml/_internal/models/model.py	88.07% <0.00%> (-1.76%)	⬇️
bentoml/_internal/runner/runner.py	90.90% <0.00%> (-0.91%)	⬇️
bentoml/__init__.py
bentoml/tensorflow.py
bentoml/serve.py
bentoml/mlflow.py
... and 13 more