feat(memory)!: Uses the new MemoryEntry schema for all memory related components.

BREAKING CHANGE. This commit changes all memory related interface to using the newly introduced MemoryEntry class.

PiperOrigin-RevId: 758464887

src/google/adk/tools/_memory_entry_utils.py

@@ -0,0 +1,30 @@
+# Copyright 2025 Google LLC
+#
+# 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 __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+  from ..memory.memory_entry import MemoryEntry
+
+
+def extract_text(memory: MemoryEntry, splitter: str = ' ') -> str:
+  """Extracts the text from the memory entry."""
+  if not memory.content.parts:
+    return ''
+  return splitter.join(
+      [part.text for part in memory.content.parts if part.text]
+  )