Remove unused imports from _batch.py; fix test imports to use _batch_base

Helpers moved to _BatchBase (_CRLF, _BOUNDARY_RE, _extract_boundary, etc.)
are no longer re-imported by _BatchClient. Two test files updated to import
these helpers directly from _batch_base where they now live.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Abel Milash

src/PowerPlatform/Dataverse/data/_batch.py

@@ -34,14 +34,7 @@
     _QuerySql,
     _ChangeSet,
     _ChangeSetBatchItem,
-    _CRLF,
     _MAX_BATCH_SIZE,
-    _BOUNDARY_RE,
-    _raise_top_level_batch_error,
-    _extract_boundary,
-    _split_multipart,
-    _parse_mime_part,
-    _parse_http_response_part,
 )
 
 if TYPE_CHECKING:

tests/unit/data/test_batch_edge_cases.py

@@ -18,12 +18,14 @@
     _ChangeSetBatchItem,
     _RecordDelete,
     _RecordGet,
+    _MAX_BATCH_SIZE,
+)
+from PowerPlatform.Dataverse.data._batch_base import (
     _extract_boundary,
     _raise_top_level_batch_error,
     _split_multipart,
     _parse_http_response_part,
     _CRLF,
-    _MAX_BATCH_SIZE,
 )
 from PowerPlatform.Dataverse.core.errors import HttpError, ValidationError
 from PowerPlatform.Dataverse.data._raw_request import _RawRequest

tests/unit/data/test_batch_serialization.py

@@ -29,6 +29,8 @@
     _TableGetRelationship,
     _TableCreateLookupField,
     _QuerySql,
+)
+from PowerPlatform.Dataverse.data._batch_base import (
     _extract_boundary,
     _raise_top_level_batch_error,
     _parse_mime_part,