Fix hydra runner
This pull request **introduces 2 alerts** when merging 1548c44f5dc90b95d7fc3d8fd1f1e83347753c74 into eb927fe6aa69f8d73705dcb785a2afb95e4c279d - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-2b1f14de5396282d23465f680fcf532753f62246)

**new alerts:**

* 1 for Non\-callable called
* 1 for Unused import
This PR fixes hydra runner, enabling to use schemas with manual passing of configs files using command line.

- [x] Modified hydra_runner so it injects schema into the right "place" in ConfigStore.
- [x] Covers runner with integration tests

Usage: please take a look at tests and the used "example"  (`tests/hydra/my_app.py`)

Additionally cleans up some hydra settings in NeMo:
- [x] Sets hydra logging outputs only to stdout (no empty log file in  . dir!!)
- [x] Disables the creation of .hydra subdir 
- [x] Removes the old set_config wrapper
