Add launchSettings.json for ReceiverUIBlazor project

Configured development launch profile with browser launch, environment variable, and HTTP/HTTPS URLs for EnvelopeGenerator.ReceiverUIBlazor.

EnvelopeGenerator.ReceiverUIBlazor/Properties/launchSettings.json

@@ -0,0 +1,12 @@
+{
+  "profiles": {
+    "EnvelopeGenerator.ReceiverUIBlazor": {
+      "commandName": "Project",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      },
+      "applicationUrl": "https://localhost:49582;http://localhost:49583"
+    }
+  }
+}