Generate version header when configuring project

The basic idea is we create a version header template at
"src/base/version.h.in" and the build systems are expected to replace
strings that are enclosed with @ symbols and generate
"src/base/version.h" for other source files to consume/include.

src/app/CMakeLists.txt

@@ -61,7 +61,6 @@ target_sources(qbt_app PRIVATE
 
 target_link_libraries(qbt_app PRIVATE
     qbt_base
-    qbt_version_definitions
 )
 
 set_target_properties(qbt_app PROPERTIES RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}")

src/app/application.cpp

@@ -81,6 +81,7 @@
 #include "base/utils/fs.h"
 #include "base/utils/misc.h"
 #include "base/utils/string.h"
+#include "base/version.h"
 #include "applicationinstancemanager.h"
 #include "filelogger.h"
 

src/app/main.cpp

@@ -78,6 +78,7 @@ Q_IMPORT_PLUGIN(QICOPlugin)
 
 #include "base/preferences.h"
 #include "base/profile.h"
+#include "base/version.h"
 #include "application.h"
 #include "cmdoptions.h"
 #include "upgrade.h"

src/app/stacktracedialog.cpp

@@ -32,6 +32,7 @@
 #include <QString>
 
 #include "base/utils/misc.h"
+#include "base/version.h"
 #include "ui_stacktracedialog.h"
 
 StacktraceDialog::StacktraceDialog(QWidget *parent)