Database Manager

done:
+ master.sql as resource
+ implemented incremental database changes also for Master
+ dbUp sql script variables implemented
+ improved database handling and creation code
+ simpified database creation
+ almost all Database and Tenant creation moved to DatabaseManager.cs (rest code marked with TODO)
+ Unattended install of master can be performed by settings in appsettings.json
+ Improved IsInstalled checking
+ Removed DBSchema field from Tenant
+ Default database and site creation moved to Program.Main

Oqtane.Server/Extensions/OqtaneServiceCollectionExtensions.cs

@@ -115,7 +115,7 @@ namespace Microsoft.Extensions.DependencyInjection
             foreach (var file in assembliesFolder.EnumerateFiles($"*.{pattern}.*.dll"))
             {
                 // check if assembly is already loaded
-                var assembly = Assemblies.FirstOrDefault(a => a.Location == file.FullName);
+                var assembly = Assemblies.FirstOrDefault(a =>!a.IsDynamic && a.Location == file.FullName);
                 if (assembly == null)
                 {
                     // load assembly from stream to prevent locking file ( as long as dependencies are in /bin they will load as well )