Add `language_bcp47` tag (#4753)

* fix ms_terms

* fix ted_talks_iwslt

* move tags to language_bcp47

* fix bad codes

* add language_details and language_bcp47 in DatasetMetadata

* more fixes

* fix wiki_dpr

Commit from https://github.com/huggingface/datasets/commit/aa48a29d1304167dff37cef0ed7542f29376ee2d

README.md

@@ -6,11 +6,11 @@ multilinguality:
 task_ids:
 - text-classification-other-language-identification
 language:
-- hi
 - awa
 - bho
-- mag
 - bra
+- hi
+- mag
 annotations_creators:
 - unknown
 source_datasets: