Make DataProtection follow the Options model

[javiercn]

This repo requires some cleanup to adapt it to the pattern we follow on other parts of the framework

[guardrex]

@javiercn ... friendly reminder from those of us in production with bits like ...

services.AddSingleton<IXmlRepository, CustomXmlRepository>();
services.AddSingleton<IXmlEncryptor, CustomXmlEncryptor>();
services.AddSingleton<IXmlDecryptor, CustomXmlDecryptor>();

... let us know if "follow the Options model" means something is about to break (i.e., Announcements repo). Everything here is staged, but surprises can be unsettling.

[Eilon]

@guardrex indeed, we'll post announcements about any significant changes - and if we push this change through, it'll count as significant.

[guardrex]

@Eilon Cool. I have several apps in production now using these bits. Although everything is staged and tested, it still puts a scare on you 💀 when something unexpectedly goes 💥.