Sam4onnx

- Support for constant rewriting when the same constant is shared. Valid only when `op_name` is specified. Generates a new constant that is different from the shared constant.

- `Reshape_156 onnx::Reshape_391 int64 [1, -1, 85]`
- `Reshape_174 onnx::Reshape_391 int64 [1, -1, 85]`
bash
sam4onnx \
--input_onnx_file_path yolov7-tiny_test_sim.onnx \
--output_onnx_file_path yolov7-tiny_test_sim_mod.onnx \
--op_name Reshape_156 \
--input_constants onnx::Reshape_391 int64 [1,14400,85]

- `Reshape_156 onnx::Reshape_391 int64 [1, -1, 85]` -> `Reshape_156 onnx::Reshape_391_mod_3 int64 [1, 14400, 85]`
- `Reshape_174 onnx::Reshape_391 int64 [1, -1, 85]`

- `string` attributes bug fixes

- Security update
- README update

- `eval()` -> `ast.literal_eval()`

- Fixed a bug that caused rewriting of direct constants to fail

- Support for deletion of attributes