[inspector] Refactor protocol-test.js

test/inspector/debugger/promise-chain-when-limit-hit-expected.txt

+Tests how async promise chains behave when reaching the limit of stacks
 Checks correctness of promise chains when limit hit
 inspector.setMaxAsyncTaskStacks(3)
 Run expression 'console.trace()' with async chain len: 3
 {
     method : Runtime.consoleAPICalled
     params : {
         args : [
             [0] : {
                 type : string
                 value : console.trace
@@ skipping 214 matching lines @@
                         url : 
                     }
                 ]
                 description : Promise.resolve
             }
         }
         timestamp : <timestamp>
         type : trace
     }
 }