[2SP;2SP] Port gr-digitizer to the new GR with Value, Value::Map and Tensors #389
Description
GR has been refactored to replace use pmtv with the new gr::pmt::Value and gr::Tensor<T> API.
The latter replaces the use of std::vector where applicable.
See the new API documentation and PR#677. PR#, and PR#692 for details.
The same changes need to be followed up and tested for gr-digitizer. The test should include HW tests with at least one PicoScope model (whichever is easily available/connected in the lab).