### What this PR does / why we need it?
1. Rename dynamic_ep to default_eplb.
2. Rename dynamic_ep_v2 to swift_balancer
3. Discard func compose_expert_update_info_bipartite.
- vLLM version: v0.13.0
- vLLM main:
bde38c11df
Signed-off-by: shenchuxiaofugui <1311027364@qq.com>