Support for OIDC Token Exchange flow

[jefeish]

• added OIDC support
• added pino for log-level support

Sample Execution

LOG_LEVEL=info npm run dev 

Note: debug level provides request & JWT data

Log sample:

[23:40:47.057] INFO (40622): Received token exchange request at endpoint '/exchange' (OIDC flow)
[23:40:47.057] INFO (40622): Fetching signing key for token verification ('https://github.com/login/oauth/.well-known/jwks.json')
[23:40:47.330] INFO (40622): Verifying token signature, using signing key
[23:40:47.332] INFO (40622): Validating JWT payload
[23:40:47.332] INFO (40622): JWT is valid
[23:40:47.332] INFO (40622): Token exchange successful