[resolvers]: Delegates as resolvers

[pekkah]

• Add Delegate as resolver
• Delegate can take ResolverContext argument
• Delegate can take any property of ResolverContext as argument (by name, ignores case)
• Delegate can take additional arguments which are resolved from ResolverContext.RequestServices
• Delegate return value can be void, ValueTask, Task
• Delegate return value can be T, ValueTask, Task and the returned value is assigned to ResolverContext.ResolvedValue automatically