use jmespath library to support parsing multi-level userInfo when usi…

[JevonXing]

Signed-off-by: zheyuan.xing [email protected]

Overview

https://github.com/dexidp/dex/issues/2563

What this PR does / why we need it

1. use jmespath library to support parsing (解析) multi-level username key and so on when using oauth
2. add unit test for oauth

Special notes for your reviewer

Does this PR introduce a user-facing change?

[nabokihms]

@pokixing, thank you for submitting this PR. JMESPath is a powerful query language that allows users to extract data from JSON documents.

Firstly, we must assess all risks provided by adding this solution to the code base, e.g., new configuration abilities, a new surface of attacks, and prospects of the jmespath in Dex. As for me, I like the idea, but I'd like to start with a design doc first.

P.S. I think I didn't understand the original problem. Is there something wrong with using 解析 as a key?