[Transform] Handle bulk indexing errors due to mapping conflicts

[hendrikmuhs]

If a transform runs into a bulk indexing failure it handles the failure as non-persistent except for:

• script errors (see [Transform] improve error handling of script errors #48887)
• circuit breaker exceptions

Mapping conflicts should be added to these checks.

[elasticmachine]

Pinging @elastic/ml-core (:ml/Transform)