Move single FAB API under the separate class

SingleFab class provides functionalities to support single FAB feature.
This commit moves the single FAB related API under SingleFab class.

Change-Id: I8d55cd2134f5812f83f5fc5033df097ab1b1f8f2
Signed-off-by: Anupama B R <anupama.b.r1@ibm.com>
diff --git a/vpd-manager/meson.build b/vpd-manager/meson.build
index 6c860da..cb86f87 100644
--- a/vpd-manager/meson.build
+++ b/vpd-manager/meson.build
@@ -28,6 +28,7 @@
 parser_build_arguments = []
 if get_option('ibm_system').allowed()
     parser_build_arguments += ['-DIBM_SYSTEM']
+    vpd_manager_SOURCES += 'src/single_fab.cpp'
 endif
 
 vpd_manager_exe = executable(