fix(ts): tweak Adapter related types

[balazsorban44]

Reasoning 💡

1. The first parameter of an adapter will always be something like a client that is used to communicate with a database, so we can require it. The second parameter will be reserved for any additional configuration for the adapter.

2. some parameters in the AppOptions interface were nullable, but in reality, we set a default for almost all of them here:
   

   next-auth/src/server/index.js

   Lines 93 to 136 in 6647305

   	req.options = {
   	debug: false,
   	pages: {},
   	theme: 'auto',
   	// Custom options override defaults
   	...userOptions,
   	// These computed settings can have values in userOptions but we override them
   	// and are request-specific.
   	adapter,
   	baseUrl,
   	basePath,
   	action,
   	provider,
   	cookies,
   	secret,
   	providers,
   	// Session options
   	session: {
   	jwt: !adapter, // If no adapter specified, force use of JSON Web Tokens (stateless)
   	maxAge,
   	updateAge: 24 * 60 * 60, // Sessions updated only if session is greater than this value (0 = always, 24*60*60 = every 24 hours)
   	...userOptions.session
   	},
   	// JWT options
   	jwt: {
   	secret, // Use application secret if no keys specified
   	maxAge, // same as session maxAge,
   	encode: jwt.encode,
   	decode: jwt.decode,
   	...userOptions.jwt
   	},
   	// Event messages
   	events: {
   	...defaultEvents,
   	...userOptions.events
   	},
   	// Callback functions
   	callbacks: {
   	...defaultCallbacks,
   	...userOptions.callbacks
   	},
   	pkce: {},
   	logger
   	}

This means that the internal interface for AppOptions can be assumed to have much more non-nullable fields and thus playing better with the Adapter interface and when it is used to type custom adapters.

Checklist 🧢

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• Documentation
• Tests
• Ready to be merged
  

Affected issues 🎟

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[ubbe-xyz]

Coolios 📐