Core: Refactor CpuCoreManager to CpuManager and Cpu to Core Manager.

This commit instends on better naming the new purpose of this classes.

src/core/CMakeLists.txt

@@ -15,14 +15,14 @@ add_library(core STATIC
     constants.h
     core.cpp
     core.h
-    core_cpu.cpp
-    core_cpu.h
+    core_manager.cpp
+    core_manager.h
     core_timing.cpp
     core_timing.h
     core_timing_util.cpp
     core_timing_util.h
-    cpu_core_manager.cpp
-    cpu_core_manager.h
+    cpu_manager.cpp
+    cpu_manager.h
     crypto/aes_util.cpp
     crypto/aes_util.h
     crypto/encryption_layer.cpp