Extend CaseType API to return/save XML

The CaseType.get and CaseType.create APIs should be able to return/save the case definition. From the API perspective, this is a nested array. (In the DB, the nested array should be saved as XML. In REST, the nested array can be JSON.) The structure we mocked up for the array is included below.

---

{
id: 123,
label: 'Adult Day Care Referral',
description: '',
definition: { // This is the serialized field
name: 'Adult Day Care Referral',
activityTypes: [

{name: 'Open Case', max_instances: 1 }

,

{name: 'Medical evaluation'}

,
...
],
activitySets: [
{
name: 'standard_timeline',
label: 'Standard Timeline',
timeline: 1,
activityTypes: [

{name: 'Open Case', status: 'Completed' }

,

{name: 'Medical evaluation', reference_activity: 'Open Case', reference_offset: 3, reference_select: 'newest ... ] }

],
caseRoles: [

{ name: 'Senior Services Coordinator', creator: 1, manager: 1 }

,

{ name: 'Health Services Coordinator' }

,

{ name: 'Benefits Specialist' }

]
}
}

---

Some key points:

• The "XML" content is embedded as part of the "definition" field
• The XML uses tags like <ActivitySets>/<ActivitySet> or <ActivityTypes>/<ActivityType>. This uses a property "activitySets" with an array.