create column-based onedit handler

src/sheetUtils.ts

@@ -85,3 +85,12 @@ export function getRowByColumnValue(
   console.log("row found: " + resultRow)
   return resultRow
 }
+
+export function getColumnName(sheetName: string, col: number) {
+  let sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName(sheetName)
+  if (!sheet) {
+    return
+  }
+  let headers = sheet.getRange("A1:1").getValues()
+  return String(headers[0][col-1])
+}