Modify organisation description with parent and child relationships

* Modification to describe organisations of type ‘other’ without reference to the word ‘other’.
* Addition of a helper method to include the organisation’s parental and child relationships in its description.
* Use of the additional helper method to describe the organisation with its parental and child relationships.
* Supporting tests to ensure organisations are described correctly.

https://www.agileplannerapp.com/boards/173808/cards/8988