[Feature] remove dependency on enable_mm and refine multimodal's code (#3014)

* remove dependency on enable_mm

* fix codestyle check error

* fix codestyle check error

* update docs

* resolve conflicts on model config

* fix unit test error

* fix code style check error

---------

Co-authored-by: shige <1021937542@qq.com>
Co-authored-by: Jiang-Jia-Jun <163579578+Jiang-Jia-Jun@users.noreply.github.com>

fastdeploy/multimodal/base.py

@@ -0,0 +1,64 @@
+"""
+# Copyright (c) 2025  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 abc import ABC, abstractmethod
+from pathlib import Path
+from typing import Generic, TypeVar
+
+_T = TypeVar("_T")
+
+
+class MediaIO(ABC, Generic[_T]):
+    @abstractmethod
+    def load_bytes(self, data: bytes) -> _T:
+        """
+            将字节数据加载为对象，并返回该对象。
+        如果加载失败，则抛出异常。
+
+        Args:
+            data (bytes): 要加载的字节数据。
+
+        Raises:
+            NotImplementedError: 当前类未实现此方法。
+
+        Returns:
+            _T: 加载后的对象。
+        """
+        raise NotImplementedError
+
+    @abstractmethod
+    def load_base64(self, media_type: str, data: str) -> _T:
+        """
+        List of media types:
+        https://www.iana.org/assignments/media-types/media-types.xhtml
+        """
+        raise NotImplementedError
+
+    @abstractmethod
+    def load_file(self, filepath: Path) -> _T:
+        """
+            加载文件，返回解析后的数据。
+
+        Args:
+            filepath (Path): 文件路径，必须是一个绝对路径。
+
+        Raises:
+            NotImplementedError: 当前方法未被实现。
+
+        Returns:
+            _T: 任意类型，表示解析后的数据。
+        """
+        raise NotImplementedError