Split Rationale page into "Context and Objective" and "Situation" pages

[mlhaufe]

Currently a generic Rationale page is being used and is represented by a predefined list of Justification created when the Solution is:

This needs to be split into a "Context and Objective" page, and "Situation" page:

Context and Objective

Why the project is needed. Recalls the buisiness context, and presents the general business objectives.

For now this will be represented by a single textarea and Goal entity.
Existing fields (Justification entities), minus the situation will be combined into a single value:

# Vision

...

# Mission

...

# Objective

...

Situation

The current situation, upon which the system is expected to improve.

Represented by a single Obstacle entity.

Populate with the existing situation Justification value.