UI styling. and streamline.

Services/FluviusDataHandler.cs

@@ -85,7 +85,7 @@ namespace BattSim.Services
             await reader.ReadLineAsync();
             // Read all lines into memory
             var lines = new List<string>();
-            string line;
+            string? line;
             while ((line = await reader.ReadLineAsync()) is not null)
             {
                 lines.Add(line);