Restructure elytron subsystem

Change the categories and the distribution of resources in the configuration and runtime section of the elytron subsystem.

Right now, the console uses the following categories under configuration:

1. Global Settings
2. Factories / Transformers
   1. Factories
   2. Transformers
3. Mappers / Decoders
   1. Mappers
   2. Decoders
4. Other Settings
   1. Authentication Configuration
   2. Authentication Context
   3. Stores
   4. SSL
   5. Security Domains
   6. Logs
5. Security Realms
   1. Security Realms
   2. Realm Mappers

The distribution is imperfect, especially in the "Other Settings" section. Often it is resource type specific and not use case driven. 

This enhancement should come up with more use case-centric categories, making it easy for the user to find what he is looking for. Finally, the new categories should also consider new security-related subsystems that will be added in future versions.