Revert "chore: refactor variable processing, add notes"

This reverts commit 8b81c77.

packages/backend/src/helpers/compute-parameters.ts

@@ -71,15 +71,10 @@ function findAndSubstituteVariables(
           : Array.isArray(dataValue)
           ? dataValue.join(', ')
           : dataValue
-
-        /**
-         * NOTE: this is to deal with escaping variables in custom api data field
-         * be careful with this as it may break other apps if the key 'data' is used
-         */
-        if (parameterKey === 'data') {
-          return JSON.stringify(processedVar).slice(1, -1)
-        }
-        return processedVar
+        return parameterKey === 'data'
+          ? // removes " " for custom api data field as its already wrapped
+            JSON.stringify(processedVar).slice(1, -1)
+          : processedVar
       }
 
       return part