IGBF-1206 - implement ID to prevent Data Provider duplication

Add framework for id attribute for default data providers

Re-write logic flow for reading user prefs node

Change object type in DataProviderManager so that the methods for getting a default data provider id only need to be specified for the BaseDataProvider type, without any changes to the DataProvider Interface

fix typo

Set the default data provider id in the constructor to ensure it is saved in preferences

Remove test line.

Use a new method (rather than a new map) to test for registred data providers with a given id

Remove isEditable tags from igbDefaultPrefs.json file

Add ability to preserve custom password and login from user prefs for default data providers

Setting return type of getDataProviderById method to BaseDataProvider

Removing IS_DEFAULT_SERVER from DataProviderPrefKeys as it is not used anywhere, and DEFAULT_PROVIDER_ID can be used in its place henceforth

Changing control flow of initialize data provider and adding comments about isEditable

Making loadIGBPrefs method private

Remove migrateOldDataProviders method

Set editable to false explicitly rather than accidently