New methods that return kth element from the last node of a list

Two methods implemented, decribed in main class.
Revert "New methods that return kth element from the last node of a list"

This reverts commit 0f7f787a2d3dd15c55cf9e034f7218c619405155.
Revert "Revert "New methods that return kth element from the last node of a list""

This reverts commit 1718851667870f4c5ac4bb12c706dfc2b80b7514.