Encapsulate concept of default source by moving to array responses of `content` and `translations`

[Harjot1Singh]

Summary

As there are multiple sources of both content and translations, an end user may not know which source to use for content and translations, per composition. A clean way of modelling around this is to represent content and translation values as arrays, ordered by our recommendation for the line.

Approach

Change the JSON representation to use arrays, rather than objects to represent the value of content/gurbani and translations.