Move k-NN and sparse vector fields to the top level (#11420)

* Move vector field types to the top level

Signed-off-by: Fanit Kolchina <[email protected]>

* Make k-NN vector parent page

Signed-off-by: Fanit Kolchina <[email protected]>

---------

Signed-off-by: Fanit Kolchina <[email protected]>
(cherry picked from commit 1ae559a)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]