* Integration of configurable AzureAd External Provider

* Documentation Updated for AzureAD Provider

* Implementation of Csp for Images

* Configuration for CSP based on appsettings configuration

* merge issue fixed in json

* Added documentation for CSP

* CSP Added in Admin project

* gravatar.com trusted added domain

* URI for default CSP fixed

* Missing trusted domains default added

* added unsafe script to csp + stylesource

* Integration of configurable AzureAd External Provider

* Documentation Updated for AzureAD Provider

* Added allow anonymous to Logout action

* Added CustomSignInManager

* Changed overrided method in CustomSignInManager

* Simplified SignInWithClaimsAsync method

moved extension method for adding email senders to shared project and included it to Admin,Api and STS

Base64UrlEncode all codes for identity; Add view for email confirmation based on commits #631 from @martinussuherman

add new shared projects to sts, remove email configuration and senders, use email configuration and senders from new shared project

Added the possiblity to configure the IdentityServer Public Origin via the new AdvancedConfiguration

DataProtection keys are now stored in a central database (new IdentityServerDataProtectionDbContext was created)

Fixed PosgreSql queries syntax

DB healthchecks now target the correct type of db provider according to the DatabaseProviderConfiguration.ProviderType setting

SqlServer, DbContext and IdentityServer health checks added to IdentityServer, Admin and Admin.Api projects.

Possibility to configure the default culture;
If there is only one supported culture, do not show the language selection combo