As part of assigning code ownership via the OWNERS.yml files, we are finding examples of directories with lots of source files owned by various teams. It seems simpler if ownership is usually ascribed on a directory basis, which implies that we should be better organizing the code into directories along team ownership lines.

This ticket proposes moving the following source files related to ClientCursor and cursor management into a new directory at path src/mongo/db/query/clientcursor owned entirely by the QueryExecution team:

src/mongo/db/allocate_cursor_id.[h|cpp]
src/mongo/db/clientcursor.[h|cpp]
src/mongo/db/cursor_id.h
src/mongo/db/cursor_manager.[h|cpp]
src/mongo/db/cursor_manager_test.cpp
src/mongo/db/cursor_server_params.[h|cpp|idl]
src/mongo/db/generic_cursor.[h|idl]

The implementer of this ticket should check whether there are additional ClientCursor-related files that should move as well. I would suggest keeping the structure of the libdeps graph unchanged even though the source code is moving.