Make the Python Wrapper more Hackable and simplify Quantization (#1010)

* Some first `Module` implementations

* Add `state_dict` and `load_state_dict` functionality

* Move modules around and create `candle.nn.Linear`

* Add `nn.Embedding` and `nn.LayerNorm`

* Add BERT implementation

* Batch q-matmul

* Automatically dequantize `QTensors` if a `Tensor` is expected

* Add Module `.to()`, `.cuda()`, `cpu()` and `.type()` functionality

* Unittests for `Module`, `Tensor` and `candle.utils`

* Add `pytorch` like slicing to `Tensor`

* Cleanup and BERT fixes

* `black` formatting + unit-test for `nn.Linear`

* Refactor slicing implementation

.vscode/settings.json

@@ -0,0 +1,11 @@
+{
+    "[python]": {
+        "editor.defaultFormatter": "ms-python.black-formatter"
+    },
+    "python.formatting.provider": "none",
+    "python.testing.pytestArgs": [
+        "candle-pyo3"
+    ],
+    "python.testing.unittestEnabled": false,
+    "python.testing.pytestEnabled": true
+}