[FieldHelper] Reworked and split up field helper into many utils.
- New helpers: FieldLocator, FieldSchemaHelper, FieldLookupHelper
- Added support for string and Taxonomy (single + multi) default values (and term store mappings)
- Still missing DefaultValue ensure logic for most other field types (DateTimeFieldInfo, UrlFieldInfo, etc.). All this conversion logic should ideally be shared with the Binding.Converters types, but we'll see.
- Moved solution folders around to group test projects together
Merge branch 'develop' of https://github.com/GSoft-SharePoint/Dynamite into develop