Move version constants into its own compile-unit

Speeds up the build by moving those constants into a separate compile-unit.
Currently, since the version header is auto regenerated on each build,
all modules that include it, also have to be recompiled every time.

scripts/addversion.py

@@ -2,7 +2,7 @@ import os
 import subprocess
 from time import time
 
-FILENAME_VERSION_H = 'lib/AmsConfiguration/include/version.h'
+FILENAME_VERSION_H = 'lib/FirmwareVersion/src/generated_version.h'
 version = os.environ.get('GITHUB_TAG')
 if version == None:
     try:
@@ -15,9 +15,7 @@ if version == None:
       version = "SNAPSHOT"
 
 hf = """
-#ifndef VERSION
-  #define VERSION "{}"
-#endif
+#define VERSION_STRING "{}"
 #define BUILD_EPOCH {}
 """.format(version, round(time()))
 with open(FILENAME_VERSION_H, 'w+') as f: