Cloud

[franklevasseur]

Cloud version of botpress NLU

• [x] handle lang server and duckling errors in nlu-server (in this PR)
• [x] languages as path parameters of all routes of language server (in this PR)
• [x] one process per training (even if successful) prevent launching training on dead process
• [x] remove ghost, replace by a table with schema | appid | modelId | content | (might help solving this issue)
• [x] fully remove legacy election support
• [x] allow launching language server and download on start
• [x] fully remove defaults from nlu-cli package (defaults should go in packages)
• [x] remove support for NLU_SERVER_CONFIG, replace by proper usage of environment variables
• [x] upgrade node to v16.13.0
• [x] rename current e2e to benchmarks and write some sort of e2e tests for nlu-server
• [x] make sure to handle unhandled rejections
• [x] allow linting a dataset to return issues and help the user build a better dataset