chore: update changelog

chore: raise version

feat: upgrade to stable version 4 of identityserver4

chore: update to dotnet-sdk 3.1.301

feat: add overload to IdentityServerTestHostBuilder to build a host w…

…ith a custom container

feat: add IdentityServerTestHostCustomContainerBuilder which allows b…

…uilding a test host with a custom container

feat: add support for IHostBuilder

* Support for `IdentityServer4` version 4 preview 3
* Rename `IdentityServerHostBuilder` to `IdentityServerTestWebHostBuilder`
* Add sealed class `IdentityServerHostBuilder` that extends `IdentityServerTestWebHostBuilder` and mark it as obsolete
* Add new class `IdentityServerTestHostBuilder` which supports building an `IHostBuilder`
* Abstract common logic for `IdentityServerTestWebHostBuilder` and `IdentityServerTestHostBuilder`
* Rename `IdentityServerProxy` to IdentityServerWebHostProxy`
* Add sealed class `IdentityServerProxy` that derives from `IdentityServerWebHostProxy`
* Add new class `IdentityServerHostProxy` which takes an `IHostBuilder` rather than an `IWebHostBuilder`
* Abstract common logic for `IdentityServerWebHostProxy` and `IdentityServerHostProxy`

fix: make logger test not assert for generated file

feat: update deps to 3.1

chore: update deps, docs and raise version to 3.0.2