fix(api): fix ToolNode._extract_variable_selector_to_variable_mapping

The original selector syntax does not match our current implementation
for injecting user inputs into VariablePool.

api/core/workflow/nodes/tool/tool_node.py

                 for selector in selectors:
                     result[selector.variable] = selector.value_selector
             elif input.type == "variable":
-                result[parameter_name] = input.value
+                selector_key = ".".join(input.value)
+                result[f"#{selector_key}#"] = input.value
             elif input.type == "constant":
                 pass