Port remaining three core/video_input algorithms

Christos will work on updating config_helpers.txx to be able to handle a vector of algorithms which is created in get_configuration(). This update will also help with other algorithms, such as close_loops_multimethod.

Modified video_input_splice, video_input_metadata_filter and video_input_buffered_metadata_filter for porting to v2. Unit test was enabled and passes for video_input_splice. Create tests were written for the other two algorithms.