-Updated most samples for AspNetCore3.
-Improved service replacement via `DecorateService` extension on `IServiceCollection`.
- Working version of some functionality (eg ambient link generator)

Fixed but described in #189.

Also added some code around MultiTenantIdentityUser and MultiTenantIdentityRole to mirror Identity's IdentityUser and IdentityRole default entities.

Fixes #189

- Refactored multi tenant behavior into extension classes
  - No longer need to derive from `MultiTenantDbContext` or `MultiTenantIdentityDbContext` (although it is supported)
  - Added `EntityModelBuilder.IsMultiTenant()` extension method that can be used in OnModelCreating to set multitenant behavior at run time in `OnConfiguring(...)`.
  - Types with [MultiTenant] get work similarly by calling `ModelBuilder.ConfigureMultiTenant()` in `OnConfiguring(...)`.
  - `DbContext.EnforceMultiTenant` can be called before `SaveChanges(...)` or `SaveChangesAsync(...)` to actually apply multitenant logic.

- MultiTenantIdentityDbContext now applies IsMultiTenant() to each of the standard Identity types.
  - MultiTenantIdentityUser and similar all marked obsolete.

- Added unit test for an entity using the extension method

- Updated IdentityDataIsolationSample for netcoreapp2.2 and netcoreapp3.0

- Updated DataIsolationSample for netcoreapp3.0

- Updated documentation.

Closes #184

- Adds a new store that uses the app's configuration as the backing store.
- Deprecates InMemoryStore configuration functionality.

- Updated all libraries, tests, and samples for netcoreapp3.1
- Removed netcoreapp2.2 from everything, changed samples to netcoreapp2.1

Closes #208

**5.0.0**
* Added support for ASP.NET Core 3.1.
* Major refactor of how Entity Framework multitenant data isolation works. No longer need to derive from `MultiTenantDbContext` greatly improving flexibility. `IdentityMultiTenantDbContext` reworked under this new model and no longer requires or recommends use of multitenant support classes, e.g. `MultiTenantIdentityUser`. Attempted to minimize impact, but if using `IdentityMultiTenantDbContext` **this may be a breaking change!** Thanks **@GordonBlahut**!
* Simplified `EFCoreStore` to use `TenantInfo` directly. **This is a breaking change!**
* Fixed a bug with user id not being set correctly in legacy 'IdentityMultiTenantDbContext'.
* Added `ConfigurationStore` to load tenant information from app configuration. The store is read-only in code, but changes in configuration (e.g. appsettings.json) are picked up at runtime. Updated most sample projects to use this store.
* Deprecated `InMemoryStore` functionality that reads from configuration.
* Added `HttpRemoteStore` which will make an http request to get a `TenantInfo` object. It can be extended with `DelegatingHandler`s (i.e. to add authentication headers). Added sample projects for this store. Thanks to **@colindekker**!
* Fixed an exception with OpenIdConnect remote authentication if "state" is not returned from the identity provider. The new behavior will result in no tenant found for the request.
* Updated samples.
* Updated documentation.
* Updated unit tests.