Task/mongo persist compound values

**Unit test:**

It passes all the test included in this PR:

```
make unit_test TEST_FILTER=mongoUpdateContextCompoundValuesRequest.*
```

A complete pass with `make unit_test` is not working, some not related test breaks (memory corruption bug?). However, Skipping the 2 problematic tests, all tests pass (except mongoQueryContextCompoundValuesRequest which fail because only a stub is included in this PR, actual implementation with be included in a future task).

```
make unit_test TEST_FILTER=-RestService.payloadParse,RestService.noSuchServiceAndNotFound
```

**Harness**

Although some "glitch" has been detected in some compiling environment, it seems that 100% cases pass.