feat: general improvements, extensions, and additional tests

Author: ReneSchwarzer

src/WebUI.App/config/webexpress.config.xml

@@ -3,10 +3,10 @@
 	<log modus="Off" debug="false" path="/var/log/" encoding="utf-8" filename="webexpress.log" timepattern="dd.MM.yyyy HH:mm:ss" />
 	<uri>http://localhost/</uri>
 	<endpoint uri="http://localhost/"/>
-	<limit>
-		<connectionlimit>300</connectionlimit>
-		<uploadlimit>3000000000</uploadlimit>
-	</limit>
+	<kestrel>
+		<maxconcurrentconnections>300</maxconcurrentconnections>
+		<maxrequestbodysize>3000000000</maxrequestbodysize>
+	</kestrel>
 	<culture>en</culture>
 	<packages>./packages</packages>
 	<assets>./assets</assets>