openim-docker upgrade, Advanced features, as well as custom extensions

[cubxxw]

Signed-off-by: Xinwei Xiong(cubxxw-openim) 3293172751nss@gmail.com

🔍 What type of PR is this?

/kind cleanup /kind documentation /kind feature /kind bug

👀 What this PR does / why we need it:

• [x] My pull request adheres to the code style of this project
• [x] My code requires changes to the documentation
• [x] I have updated the documentation as required
• [x] All the tests have passed

🅰 Which issue(s) this PR fixes:

Resolves OpenIMSDK/Open-IM-Server#995, resolves OpenIMSDK/Open-IM-Server#996, resolves OpenIMSDK/Open-IM-Server#997, resolves OpenIMSDK/Open-IM-Server#998

📝 Special notes for your reviewer:

git clone feat/test https://github.com/openim-sigs/openim-docker 

[pull-request-size[bot]]

Whoa! Easy there, Partner!

This PR is too big. Please break it up into smaller PRs.