[IDEA] Allow launcher to authenticate using domain accounts

[kpalang]

Describe your use case
Imagine this scenario:

• You're on a computer logged into a domain account (AD)
• You already have LDAP plugin installed on the Connect server so basically user management already happens somewhere else

Now it would be really cool, if you could skip the login screen and go straight to MC Admin.
Of course regular user/pass login would still be the default.

Describe the solution you'd like
Have an option to somehow use the domain account you're already logged into on your computer. Maybe grab the current domain username and pass that to the LDAP plugin for auth. And if that fails, fall back to regular user/pass.

Describe alternatives you've considered
There right now aren't any alternatives since this isn't a serious issue, rather than a wouldn't-it-be-cool-if.