Feat: Delete the operator node and hide the corresponding sheet #3221 (#9142)

### What problem does this PR solve?

Feat: Delete the operator node and hide the corresponding sheet #3221
### Type of change


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

web/src/pages/agent/canvas/node/begin-node.tsx

@@ -33,7 +33,7 @@ function InnerBeginNode({ data, id, selected }: NodeProps<IBeginNode>) {
         id={NodeHandleId.Start}
       ></CommonHandle>
 
-      <section className="flex items-center justify-center gap-2">
+      <section className="flex items-center  gap-2">
         <OperatorIcon name={data.label as Operator}></OperatorIcon>
         <div className="truncate text-center font-semibold text-sm">
           {t(`flow.begin`)}

web/src/pages/agent/canvas/node/note-node/index.tsx

@@ -56,7 +56,7 @@ function NoteNode({ data, id, selected }: NodeProps<INoteNode>) {
       <section className="px-1 py-2 flex gap-2 bg-background-highlight items-center note-drag-handle rounded-s-md">
         <NotebookPen className="size-4" />
         <Form {...nameForm}>
-          <form>
+          <form className="flex-1">
             <FormField
               control={nameForm.control}
               name="name"