Better naming `ads` and `workload` modes

CUrrently `ads` and `workload` are both very strange to users.
ads mode is to handle both L4 and L7 in the node within ebpf and kernel module
workload mode is to intrecept traffic and handle L4 in the node within ebpf, but will forward L7 processing to kmesh-waypoint.

Start by locating all user-facing references to the `ads` and `workload` modes, then compare them with the L4/L7 processing behavior described in the issue. Done means the modes have clearer names that accurately distinguish node-local L4/L7 handling from forwarding L7 processing to kmesh-waypoint.

Written by the indexing model from the issue text.