Block Transformers: distinguish between READ and WRITE versions

TNL-6522

lms/djangoapps/course_api/blocks/transformers/block_counts.py

@@ -8,7 +8,8 @@ class BlockCountsTransformer(BlockStructureTransformer):
     """
     Keep a count of descendant blocks of the requested types
     """
-    VERSION = 1
+    WRITE_VERSION = 1
+    READ_VERSION = 1
     BLOCK_COUNTS = 'block_counts'
 
     def __init__(self, block_types_to_count):

lms/djangoapps/course_api/blocks/transformers/block_depth.py

@@ -9,7 +9,8 @@ class BlockDepthTransformer(BlockStructureTransformer):
     Keep track of the depth of each block within the block structure.  In case
     of multiple paths to a given node (in a DAG), use the shallowest depth.
     """
-    VERSION = 1
+    WRITE_VERSION = 1
+    READ_VERSION = 1
     BLOCK_DEPTH = 'block_depth'
 
     def __init__(self, requested_depth=None):

lms/djangoapps/course_api/blocks/transformers/blocks_api.py

@@ -22,7 +22,8 @@ class BlocksAPITransformer(BlockStructureTransformer):
     Note: BlockDepthTransformer must be executed before BlockNavigationTransformer.
     """
 
-    VERSION = 1
+    WRITE_VERSION = 1
+    READ_VERSION = 1
     STUDENT_VIEW_DATA = 'student_view_data'
     STUDENT_VIEW_MULTI_DEVICE = 'student_view_multi_device'
 

lms/djangoapps/course_api/blocks/transformers/milestones.py

@@ -13,7 +13,8 @@ class MilestonesTransformer(FilteringTransformerMixin, BlockStructureTransformer
     Excludes all special exams (timed, proctored, practice proctored) from the student view.
     Excludes all blocks with unfulfilled milestones from the student view.
     """
-    VERSION = 1
+    WRITE_VERSION = 1
+    READ_VERSION = 1
 
     @classmethod
     def name(cls):

lms/djangoapps/course_api/blocks/transformers/navigation.py

@@ -20,7 +20,8 @@ class BlockNavigationTransformer(BlockStructureTransformer):
     Prerequisites: BlockDepthTransformer must be run before this in the
     transform phase.
     """
-    VERSION = 1
+    WRITE_VERSION = 1
+    READ_VERSION = 1
     BLOCK_NAVIGATION = 'block_nav'
     BLOCK_NAVIGATION_FOR_CHILDREN = 'children_block_nav'
 

lms/djangoapps/course_api/blocks/transformers/student_view.py

@@ -8,7 +8,8 @@ class StudentViewTransformer(BlockStructureTransformer):
     """
     Only show information that is appropriate for a learner
     """
-    VERSION = 1
+    WRITE_VERSION = 1
+    READ_VERSION = 1
     STUDENT_VIEW_DATA = 'student_view_data'
     STUDENT_VIEW_MULTI_DEVICE = 'student_view_multi_device'