Feat/memory (#11812)

### What problem does this PR solve?

Manage and display memory datasets.

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

common/constants.py

@@ -151,6 +151,23 @@ class Storage(Enum):
     OPENDAL = 6
     GCS = 7
 
+
+class MemoryType(Enum):
+    RAW = 0b0001          # 1 << 0 = 1 (0b00000001)
+    SEMANTIC = 0b0010     # 1 << 1 = 2 (0b00000010)
+    EPISODIC = 0b0100     # 1 << 2 = 4 (0b00000100)
+    PROCEDURAL = 0b1000   # 1 << 3 = 8 (0b00001000)
+
+
+class MemoryStorageType(StrEnum):
+    TABLE = "table"
+    GRAPH = "graph"
+
+
+class ForgettingPolicy(StrEnum):
+    FIFO = "fifo"
+
+
 # environment
 # ENV_STRONG_TEST_COUNT = "STRONG_TEST_COUNT"
 # ENV_RAGFLOW_SECRET_KEY = "RAGFLOW_SECRET_KEY"