CAS: NED missing

From the paper
```
Concept Unique Identifiers (CUI) corre-
sponding to French terms from the UMLS
(Lindberg et al., 1993) for single or multi-
word terms. For multi-word terms, the an-
notations exploits the IOB (Inside-Outside-
Begin) format. For instance, the two-word
term vitamine B12 is encoded as follows:
- ... O
- vitamine B-C0042845
- B12 I-C0042845
- ... O
```
but `_SUPPORTED_TASKS` has only `TEXT_CLASSIFICATION`