add openai middleware

in openai middleware, users can:

1. setup a proxy / forward server for openai service
2. use custom key to protect service, support many-to-many mapping (user custom key to openai api key)

Main change: support multi path prefix service proxy

v0.9.7

MAIN CHANGE: support multi path prefix proxy

add openapi3

v0.9.6

use github.com/sirupsen/logrus as import path

fix jwt parse failed

v0.9.5

fix parse error for jwt: if jwt is invalid

fix app login for addauth

v0.9.4

fix login for addauth

Do not check access when add middleware

v0.9.3

do not check access for addauth middleware

fix query params validate error

v0.9.2

fix writing error

support get access_token from cookies

v0.9.1

fix mismatch type

version 0.9.0

a release used in debug mode