Validate token feature

[Xemdo]

Tell us about your feature request

Right now twitch token has the ability to revoke, such as:

twitch token --client-id CLIENT_ID --revoke OAUTH_TOKEN

In a similar fashion, we should have a way to validate tokens:

twitch token --validate OAUTH_TOKEN

This would return information similar to Barry's Token Checker, which uses the /oauth2/validate endpoint.

Disclaimer

• I agree

[GStefanowich]

Is the CLI capable of doing ||s with if a CLI parameter is present?

Could you theoretically do

twitch token --validate OAUTH_TOKEN --revoke
twitch token --validate --revoke OAUTH_TOKEN

without having to do

twitch token --validate OAUTH_TOKEN --revoke OAUTH_TOKEN

[Xemdo]

Ideally, you would validate or revoke. Doing both doesn't provide much since revoke requires a valid token, and will fail if the token is not valid.

[Xemdo]

Added in #277