Fixed the timers to track proper DB execution duration.

[lingxiao-microsoft]

Why make this change?

Previously we created a PR to add timers to track the duration of DB execution. However, there are some issues within that results in incorrect time duration logged.

Please exclude the whitespaces diff to have a better reviewing experience

1. Previously we added timer in ExecuteQueryAsync and ExecuteQueryAgainstDbAsync
2. However, within function ExecuteQueryAsync, it will invoke ExecuteQueryAgainstDbAsync .
3. Which will result in logging the time duration twice.
4. See repro below
   

We can see the stored value is always twice as the stop watch

What is this change?

• Fixing the timer to log properly
  • Removed the timer from upper function ExecuteQueryAsync and ExecuteQuery
  • Put the timer inside ExecuteQueryAgainstDbAsync and ExecuteQueryAgainstDb
  • Added try-finally block to wrap the functions.

How was this tested?

• Integration Tests
• Unit Tests

Sample Request(s)

• Example REST and/or GraphQL request to demonstrate modifications
  
  • Putting a breakpoint at the ExecuteQueryAsync level
  • Time durations are matched now
    

[JerryNixon]

@sezal98

[rohkhann]

Thanks for the fix!

[lingxiao-microsoft]

/azp run

[Aniruddh25]

Looks good overall! Left a few comments.

[lingxiao-microsoft]

/azp run

[lingxiao-microsoft]

/azp run