Colink

1. Rename set_variable, get_variable-> send_variable, recv_variable: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/55
2. Add generate_token_with_signature; add test_user_management: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/41
3. Instant server error redirect, check mq connection before start: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/40
4. Fix instant server version: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/51

add Instant Registry: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/30
update check.yml: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/31
add Instant Server config: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/32
add keep alive when disconnect: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/32

Automatic serialization for `int,str` in create_entry/remote_storage_create/remote_storage_update/run_task.

Split sdk_a.py to multiple source files.

Follow the Rust SDK version from v0.2.0 to v0.2.2:

Add version to RequestInfo: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/29
Instant server: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/26
Protocol Attach: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/26
Update CI workflow: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/26
Fix update registries: https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/30

Fix use grpcio-tools strange build bug v1.48.0 triggered by CI: upgrade to v1.50.0

- add policy module functions&example https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/18
- rename to request_info https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/25
- fix example: wait_user_task https://github.com/CoLearn-Dev/colink-sdk-python-dev/issues/26
- initialization: consider failed init func https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/24
- Update self-test procedure https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pull/25