Split of nuget package

[thompson-tomo]

Is your feature request related to a problem? Please describe.
As the library is modernised/integrated it should be possible for use to drop in only the parts they want of unleash

Describe the solution you'd like
I would like to have the nuget split so that I only add what I need. Proposal would be

• Unleash = current functionality + dependencies of all below packages
• Unleash.Abstractions = generic models/Interfaces to be shared/Implemented. Is dependency for all other packaged
• Unleash.Configuration = fetches toggles From unleash and loads them into IConfiguration
• Unleash.FeatureManagement = a library which allows for registering library with DI etc
• Unleash.MetricsExporter = exports All metrics prefixed with Unleash to Unleash
• Unleash.Strategies = implementation of the supported strategies including the Microsoft wrappers

[daveleek]

Answered in #183. We're considering a future improvement with the setup/app-hosting part of the SDK with potentially additional packages for platform support (.NET Framework, .NET Core)

[daveleek]

This is not going to be addressed. We will however look at improving hosting options/setup for .NET Core/5/6/7/8 etc and .NET Framework <= 4.8 in the future, but that discussion is ongoing

[PhbsSmn]

• Unleash.Configuration

If this would be added as a configuration provider, it could become immensely powerful. Because then you would be able to use the power of the configuration framework making it possible in turn to connect it with the native Feature Management in .NET let it work seamlessly with a [FeatureGate] attribute for controllers.