Update ai_services/language sample code for Language2.0

[sahkalra24]

For Java and Python sample, added:

1. Sample for translation
2. Sample custom text classification
   • create project
   • create model
   • create endpoint
   • run inferences using batchAPI
3. Sample for NER
   • create project
   • create model
   • create endpoint
   • run inferences using batchAPI

For PL/SQL sample, added:

1. Batch APIs sample code

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[johnpeach]

@sahkalra24 This PR has failed OCA checks. Please fix it so that it can be merged.