feat: implement V2 libraries usage for library content block (#30615)

YT: https://youtrack.raccoongang.com/issue/EDX_BLND_CLI-87

- V2 libraries are available for selection in the Random Block edit modal;
- selected V2 library blocks are copied to the modulestore and saved as children of the Random Block;
- V2 library version validation works the same as for the V1 libraries (with possibility to update block with the latest version);
- filtering by problem type can't be done for V2 the same as for V1 because the v2 library problems are not divided by types;
- the problem type field is hidden for v2 libraries in the edit mode;
- unit tests added/updated.

xmodule/modulestore/split_mongo/caching_descriptor_system.py

@@ -3,12 +3,12 @@
 import logging
 import sys
 
+from crum import get_current_user
 from fs.osfs import OSFS
 from lazy import lazy
 from opaque_keys.edx.locator import BlockUsageLocator, DefinitionLocator, LocalId
 from xblock.fields import ScopeIds
 from xblock.runtime import KeyValueStore, KvsFieldData
-
 from xmodule.error_module import ErrorBlock
 from xmodule.errortracker import exc_info_to_str
 from xmodule.library_tools import LibraryToolsService
@@ -74,7 +74,10 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
         self.module_data = module_data
         self.default_class = default_class
         self.local_modules = {}
-        self._services['library_tools'] = LibraryToolsService(modulestore, user_id=None)
+
+        user = get_current_user()
+        user_id = user.id if user else None
+        self._services['library_tools'] = LibraryToolsService(modulestore, user_id=user_id)
 
     @lazy
     def _parent_map(self):  # lint-amnesty, pylint: disable=missing-function-docstring