fix: Optimize copywriting

ui/src/locales/lang/en-US/views/application-workflow.ts

@@ -439,7 +439,7 @@ You are a master of problem optimization, adept at accurately inferring user int
     },
     variableSplittingNode: {
       label: 'Variable Splitting',
-      text: 'Used to split variables',
+      text: 'Split a variable into multiple variables based on expressions',
       result: 'Result',
       splitVariables: 'Split Variables',
       inputVariables: 'Input Variable',

ui/src/locales/lang/zh-CN/views/application-workflow.ts

@@ -451,7 +451,7 @@ export default {
     },
     variableSplittingNode: {
       label: '变量拆分',
-      text: '用于拆分变量',
+      text: '对输入变量通过表达式拆分为多个变量进行输出',
       splitVariables: '拆分变量',
       inputVariables: '输入变量',
       addVariables: '添加变量',

ui/src/locales/lang/zh-Hant/views/application-workflow.ts

@@ -425,7 +425,7 @@ export default {
     loopBreakNode: { label: 'Break', text: '終止當前循環，跳出循環體', isBreak: 'Break' },
     variableSplittingNode: {
       label: '變量拆分',
-      text: '用於拆分變量',
+      text: '根據表達式將一個變量拆分為多個變量',
       result: '結果',
       splitVariables: '拆分變量',
       inputVariables: '輸入變量',