Enable the easy download of the deployment.tar.gz

[dbogunowicz]

Reverting to the state of #375 in order to enable, in the simplest way possible, the fetching of only deployment.tar.gz.
The crux of this PR is adding self.deployment_tar attribute to the Model and allowing it to be correctly initialized not only from the stub but also from the local directory.
Added unit tests that test this feature.

Manual tests:

path_where_models_are = "/home/ubuntu/.cache/sparsezoo/neuralmagic/codegen_mono-350m-bigpython_bigquery_thepile-pruned50_quantized"
if os.path.exists(path_where_models_are):
    shutil.rmtree(path_where_models_are)
    print(f"The path {path_where_models_are} has been cleaned up")
else:
    print(f"The path {path_where_models_are} does not exist")


print("1: Creating the deployment from stub")
model = Model("zoo:codegen_mono-350m-bigpython_bigquery_thepile-pruned50_quantized")
# local path to the `deployment.tar.gz` should be None (we have not downloaded anything yet)
print("Deployment directory tar path (before download): ", model.deployment_tar._path)
# grab the deployment_dir_path (this downloads the deployment.tar.gz and unpacks it)
deployment_dir_path = model.deployment_directory_path

# all should be pointing to `directory`
assert deployment_dir_path == model.deployment_tar.path == model.deployment.path
print("Deployment directory tar path: ", model.deployment_tar._path)
print("Deployment directory path: ", model.deployment.path)
print(f"deployment_dir_path: {deployment_dir_path}")

# all should display `directory` files
print("Contents of the deployment tar directory: ", os.listdir(model.deployment_tar.path))
print("Contents of the deployment directory: ", os.listdir(model.deployment.path))

# should only contain `deployment` and `deployment.tar.gz`
print("Contents of the model directory: ", os.listdir(model._path))

print("2: Creating the deployment from local path")
model = Model("zoo:codegen_mono-350m-bigpython_bigquery_thepile-pruned50_quantized")
print("Deployment directory tar path: ", model.deployment_tar.path)
deployment_dir_path = model.deployment_directory_path

assert deployment_dir_path == model.deployment_tar.path
print("Deployment directory tar path (after unzipping): ", model.deployment_tar._path)
print("Deployment directory path: ", model.deployment.path)
print(f"deployment_dir_path: {deployment_dir_path}")
print("Contents of the deployment tar directory: ", os.listdir(model.deployment_tar.path))
print("Contents of the deployment directory: ", os.listdir(model.deployment.path))
print("Contents of the model directory: ", os.listdir(model._path))

out:

The path /home/ubuntu/.cache/sparsezoo/neuralmagic/codegen_mono-350m-bigpython_bigquery_thepile-pruned50_quantized has been cleaned up
1: Creating the deployment from stub
Deployment directory tar path (before download):  None
Downloading (…)ed/deployment.tar.gz: 100%|██████████| 265M/265M [00:23<00:00, 12.1MB/s]
Deployment directory tar path:  /home/ubuntu/.cache/sparsezoo/neuralmagic/codegen_mono-350m-bigpython_bigquery_thepile-pruned50_quantized/deployment
Deployment directory path:  /home/ubuntu/.cache/sparsezoo/neuralmagic/codegen_mono-350m-bigpython_bigquery_thepile-pruned50_quantized/deployment
deployment_dir_path: /home/ubuntu/.cache/sparsezoo/neuralmagic/codegen_mono-350m-bigpython_bigquery_thepile-pruned50_quantized/deployment
Contents of the deployment tar directory:  ['vocab.json', 'model.onnx', 'config.json', 'merges.txt', 'tokenizer_config.json', 'special_tokens_map.json', 'tokenizer.json']
Contents of the deployment directory:  ['vocab.json', 'model.onnx', 'config.json', 'merges.txt', 'tokenizer_config.json', 'special_tokens_map.json', 'tokenizer.json']
Contents of the model directory:  ['deployment', 'deployment.tar.gz']
2: Creating the deployment from local path
Deployment directory tar path:  /home/ubuntu/.cache/sparsezoo/neuralmagic/codegen_mono-350m-bigpython_bigquery_thepile-pruned50_quantized/deployment.tar.gz
Deployment directory tar path (after unzipping):  /home/ubuntu/.cache/sparsezoo/neuralmagic/codegen_mono-350m-bigpython_bigquery_thepile-pruned50_quantized/deployment
Deployment directory path:  /home/ubuntu/.cache/sparsezoo/neuralmagic/codegen_mono-350m-bigpython_bigquery_thepile-pruned50_quantized/deployment
deployment_dir_path: /home/ubuntu/.cache/sparsezoo/neuralmagic/codegen_mono-350m-bigpython_bigquery_thepile-pruned50_quantized/deployment
Contents of the deployment tar directory:  ['vocab.json', 'model.onnx', 'config.json', 'merges.txt', 'tokenizer_config.json', 'special_tokens_map.json', 'tokenizer.json']
Contents of the deployment directory:  ['vocab.json', 'model.onnx', 'config.json', 'merges.txt', 'tokenizer_config.json', 'special_tokens_map.json', 'tokenizer.json']
Contents of the model directory:  ['deployment', 'deployment.tar.gz']