Deeplima dp train: The list of expected tasks should not be hard-coded

[kleag]

Currently the list of tasks the parser training model expects from the tagging model (form,upos…) is hard-coded while the tagging model can be trained with various tasks.
This list should be saved somewhere and retrieved.

This is described here:

lima/deeplima/libs/tasks/graph_dp/train/train_graph_dp.cpp

Line 77 in 7c7b1c6

// TODO retrieve tagger tasks list from model or config

And in 7c7b1c6

If tasks lists does not match, parsing fails with

terminate called after throwing an instance of 'std::logic_error'
  what():  Input classes missmatch: xpos != Definite