Improve Flow Graph conformance tests (#410)

* continue and function node

* multifunction node

* input node

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* buffering nodes

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* new input and output messages

* service nodes

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* green CI

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* graph reset tests

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* additional reset tests

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* fix codestyle issues

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* copy constructor fix

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* sfinae fix

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* fix unique_ptr on cxx11

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* style fixes

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* copy_constructor fix

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* fix atomic initialization

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>

* fid data race

Signed-off-by: Mishin, Ilya <ilya.mishin@intel.com>