[FEATURE REQ]BulkExecutor/BatchExecutor today do not expose the error message from CosmosBulItemResponse

**Is your feature request related to a problem? Please describe.**
BulkExecutor/BatchExecutor today do not expose the error message form CosmosBulItemResponse - at least for 400-BadRequest this is quite crucial. Initially the wire contract with service did not expose the error message in BulkItemResponse - but it exists now and we should consume it and pass it to the exception.
**Describe the solution you'd like**
see above

**Describe alternatives you've considered**
n/a

**Additional context**
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