misc: rename config runner file (#313)

Renamed config runner to config manager to be in sync with the latest code changes and it's role.

Author: raresgaia123

infscale/execution/config_runner.py renamed to infscale/execution/config_manager.py

@@ -27,7 +27,7 @@
 from infscale import get_logger
 from infscale.common.job_msg import Message, MessageType, WorkerStatus
 from infscale.configs.job import ServeConfig
-from infscale.execution.config_runner import ConfigManager
+from infscale.execution.config_manager import ConfigManager
 from infscale.execution.control import Channel as CtrlCh
 from infscale.execution.metrics_collector import MetricsCollector
 from infscale.execution.router import Router