[Filter] Enable C++ subplugin build

[Filter] Enable C++ subplugin build

Before adding test cases for C++ filter subplugins,
enable build for Tizen/Ubuntu.

Add enable-cppfilter=true for meson build if you
want to use this feature.

Note that the subplugin is not yet fully implemented
and needs further implementation. Thus, we do not have
testcases, yet.

Changes at v2:
- cppfilter is now default
- added isAllocatedBeforeInvoke() virtual function

Change-Id: I5e1942e0b7c957ceb675bd78496041a888978e65
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>