Vs: remove /nowin32manifest from C# flags to enable default VS behavior

Original header commit v3.10.0-rc1~494^2

if /nowin32manifest is specified, it will be preferred over any
occurring /win32manifest:<file> parameter

Templates/MSBuild/FlagTables/v10_CSharp.json

@@ -133,11 +133,14 @@
     ]
   },
   {
-    "name":  "Win32Manifest",
+    "name":  "ApplicationManifest",
     "switch": "win32manifest:",
     "comment": "",
-    "value": "true",
-    "flags": []
+    "value": "",
+    "flags": [
+      "UserValue",
+      "UserRequired"
+    ]
   },
   {
     "name":  "NoWin32Manifest",

Templates/MSBuild/FlagTables/v11_CSharp.json

@@ -133,11 +133,14 @@
     ]
   },
   {
-    "name":  "Win32Manifest",
+    "name":  "ApplicationManifest",
     "switch": "win32manifest:",
     "comment": "",
-    "value": "true",
-    "flags": []
+    "value": "",
+    "flags": [
+      "UserValue",
+      "UserRequired"
+    ]
   },
   {
     "name":  "NoWin32Manifest",

Templates/MSBuild/FlagTables/v12_CSharp.json

@@ -133,11 +133,14 @@
     ]
   },
   {
-    "name":  "Win32Manifest",
+    "name":  "ApplicationManifest",
     "switch": "win32manifest:",
     "comment": "",
-    "value": "true",
-    "flags": []
+    "value": "",
+    "flags": [
+      "UserValue",
+      "UserRequired"
+    ]
   },
   {
     "name":  "NoWin32Manifest",

Templates/MSBuild/FlagTables/v140_CSharp.json

@@ -133,11 +133,14 @@
     ]
   },
   {
-    "name":  "Win32Manifest",
+    "name":  "ApplicationManifest",
     "switch": "win32manifest:",
     "comment": "",
-    "value": "true",
-    "flags": []
+    "value": "",
+    "flags": [
+      "UserValue",
+      "UserRequired"
+    ]
   },
   {
     "name":  "NoWin32Manifest",

Templates/MSBuild/FlagTables/v141_CSharp.json

@@ -133,11 +133,14 @@
     ]
   },
   {
-    "name":  "Win32Manifest",
+    "name":  "ApplicationManifest",
     "switch": "win32manifest:",
     "comment": "",
-    "value": "true",
-    "flags": []
+    "value": "",
+    "flags": [
+      "UserValue",
+      "UserRequired"
+    ]
   },
   {
     "name":  "NoWin32Manifest",