refactor(ocr): remove unused code and simplify model architecture

- Remove unused imports and code
- Simplify model architecture by removing unnecessary components
- Update initialization and forward pass logic
- Rename variables for consistency

magic_pdf/model/sub_modules/ocr/paddleocr2pytorch/pytorchocr/postprocess/pse_postprocess/__init__.py

-# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-from .pse_postprocess import PSEPostProcess
\ No newline at end of file

magic_pdf/model/sub_modules/ocr/paddleocr2pytorch/pytorchocr/postprocess/pse_postprocess/pse/README.md

-## 编译
-This code is refer from:
-https://github.com/whai362/PSENet/blob/python3/models/post_processing/pse
-```python
-python3 setup.py build_ext --inplace
-```