documentation: fix invalid @see usages

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
test: rename file for find_overlapping_region tests

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
tests: better method names in tst_FindOverlapingRegion

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>