feat: set the anchor points of all nodes to be enterable and exitable #918 (#1119)

### What problem does this PR solve?

feat: set the anchor points of all nodes to be enterable and exitable
#918

### Type of change


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

web/src/pages/flow/canvas/index.tsx

@@ -1,6 +1,7 @@
 import { useCallback } from 'react';
 import ReactFlow, {
   Background,
+  ConnectionMode,
   Controls,
   MarkerType,
   NodeMouseHandler,
@@ -64,6 +65,7 @@ function FlowCanvas({ sideWidth, chatDrawerVisible, hideChatDrawer }: IProps) {
     <div className={styles.canvasWrapper}>
       <ReactFlow
         ref={ref}
+        connectionMode={ConnectionMode.Loose}
         nodes={nodes}
         onNodesChange={onNodesChange}
         onNodeContextMenu={onNodeContextMenu}

web/src/pages/flow/canvas/node/index.less

@@ -1,6 +1,10 @@
 .textUpdaterNode {
   // height: 50px;
-  border: 1px solid gray;
+  box-shadow:
+    -6px 0 12px 0 rgba(179, 177, 177, 0.08),
+    -3px 0 6px -4px rgba(0, 0, 0, 0.12),
+    -6px 0 16px 6px rgba(0, 0, 0, 0.05);
+
   padding: 5px;
   border-radius: 5px;
   background: white;

web/src/pages/flow/canvas/node/index.tsx

@@ -18,21 +18,25 @@ export function TextUpdaterNode({
       })}
     >
       <Handle
-        type="target"
+        id="c"
+        type="source"
         position={Position.Left}
         isConnectable={isConnectable}
         className={styles.handle}
       >
         {/* <PlusCircleOutlined style={{ fontSize: 10 }} /> */}
       </Handle>
+      <Handle type="source" position={Position.Top} id="d" isConnectable />
       <Handle
         type="source"
         position={Position.Right}
         isConnectable={isConnectable}
         className={styles.handle}
+        id="b"
       >
         {/* <PlusCircleOutlined style={{ fontSize: 10 }} /> */}
       </Handle>
+      <Handle type="source" position={Position.Bottom} id="a" isConnectable />
       <div>
         <Space>
           <OperatorIcon