Enable s2n-quic's client connection migration

[boquan-fang]

Security issue notifications

Problem:

s2n-quic's client endpoint can't performance connection migration. The RFC 9000 specifies how QUIC endpoints can perform connection migration: https://www.rfc-editor.org/rfc/rfc9000.html#name-initiating-connection-migra, while s2n-quic's client doesn't have such feature. Client endpoint might need to change its addressing information (Ip and port) for different reasons and the most common one is to switch from ethernet to WIFI. The QUIC connection migration feature provides efficient solutions to handle network changes and reduce the need to re-establish handshake in this scenario.

Need By Date:

N/A

Solution:

• Does this change what s2n-quic sends over the wire? No.
• Does this change any public APIs? --> Yes. We need at least new APIs to initiate connection migration.

Requirements / Acceptance Criteria:

1. Client should be able to actively initiate connection mgiration.
2. Connection migration tests in s2n-quic repo should perform real connection migration, instead of using packet interceptor to mimic connection migration: https://github.com/aws/s2n-quic/blob/main/quic/s2n-quic-tests/src/tests/connection_migration.rs.

Out of scope:

N/A