Unified data types [actualType and subType]

Updated tests.

JMS parsing fixes; updated {Validator,FormType}Parser, FOSRestHandler, and AbstractFormatter, and updated DataTypes enum.

Modified dataType checking.

Updated tests.

Updated DataTypes enum.

Quick fix and added doc comments.

CS fixes.

Refactored FormTypeParser to produce nested parameters. Updated tests accordingly.

Logical and CS fixes.

Sub-forms and more tests.

Ignore data_class and always use form-type to avoid conflicts.

Quick fix.

Replace #414
@bezhermoso my only concern is about this.

Before this PR, we had `collection_type[a]`. Now, it looks like we have to access `collection_type[children][a]`. This could be a BC break. Question is: does is break the sandbox?