* Add session context outbounds as slice
slice is needed for dialer proxy where two outbounds work on top of each other
There are two sets of target addr for example
It also enable Xtls to correctly do splice copy by checking both outbounds are ready to do direct copy
* Fill outbound tag info
* Splice now checks capalibility from all outbounds
* Fix unit tests
It seems the root cause is if the flag set at the inbound pipe reader, it is a race condition and freedom outbound can possibly do splice at the same time with inbound xtls writer.
Now we set the flag at the earliest and always do splice at the next buffer cycle.
- Vision now use traffic states to capture two-way info about a connection
- XTLS is de-couple with Vision, it only read traffic states to switch to direct copy mode
- fix a edge case error when Vision unpadding read 5 command bytes
- Add outbound name
- Add outbound conn in ctx
- Refactor splice: it can be turn on from all inbounds and outbounds
- Refactor splice: Add splice copy to vless inbound
- Fix http error test
- Add freedom splice toggle via env var
- Populate outbound obj in context
- Use CanSpliceCopy to mark a connection
- Turn off splice by default
* Increase some tls test timeout
* Fix TestUserValidator
* Change all tests to VMessAEAD
Old VMess MD5 tests will be rejected and fail in 2022
* Chore: auto format code
