Co-authored-by: 3Mydlo3 <[email protected]>

DiscordService, Configuration manager

* Add ReDoc documentation

* Fix version

* Set ReDoc as default start page

* Fix ReDoc DocumentTitle

* Add more verbose description

* Enable Nullable feature

* Fix Discord LogSeverity mapping switch not having default

* Set Configuration in Startup to private

* Rename test project to BotService.Tests

* Rename DAO project to Core

* Add Boderator.Core.Tests project

* Add InternalsVisibleTo attributes

* Reference Core project by BotService

* Remove clutter from BotService csproj

* Add Core reference for Core.Tests

* Reorder references in csprojs

* Change indent to 2 spaces in csprojs

* Add .editorconfig

* Add AutoFixture, Moq and FluentAssertions to test projects

* Fixes after merge

* Add CSharpFunctionalExtensions

* Start work on TestApiServer

* Remove DiscordService from startup

* Add Result extensions for easier assertions

* Fix controllers mapping

* Replace Debug controller with Health controller

* Add integration test for ping endpoint

* Add documentation for HealthController

* Change log settings

* Extract Serilog initialization to separate method

* Add log levels config

* Set indent to 2 for json files

* Move DiscordService to DiscordClient feature

* Add basic Configuration

* Add AutoAddInterfacesAsScoped()

* Enable nullable in all projects

* Update to .NET 6

* Update packages

* Fix Discord Client preventing startup