add toxiproxy to Windows (for #6114) (#6119)

I have never used Scoop before and I'm not sure how to actually test
this, but I thought this might at least get a conversation going.

Plus, if my reading of the documentation of both toxiproxy and Scoop is
correct, this may even work as is.

CHANGELOG_BEGIN
CHANGELOG_END

.dadew

@@ -3,16 +3,17 @@
     "manifests": "dev-env\\windows\\manifests",
     "tools": [
         "7zip",
-        "java-openjdk-8u201",
-        "msys2",
-        "curl-7.65.3",
-        "cacert",
-        "vcredist-14.24.28127.4",
         "bazel",
-        "nodejs-10.16.3",
-        "python-3.8.2",
-        "nsis-3.04",
+        "cacert",
+        "curl-7.65.3",
+        "java-openjdk-8u201",
         "maven-3.6.1",
-        "stack"
+        "msys2",
+        "nodejs-10.16.3",
+        "nsis-3.04",
+        "python-3.8.2",
+        "stack",
+        "toxiproxy",
+        "vcredist-14.24.28127.4"
     ]
 }

dev-env/windows/manifests/toxiproxy.json

@@ -0,0 +1,17 @@
+{
+  "homepage": "https://github.com/Shopify/toxiproxy",
+  "description": "A TCP proxy to simulate network and system conditions for chaos and resiliency testing",
+  "license": {
+    "identifier": "MIT",
+    "url": "https://raw.githubusercontent.com/Shopify/toxiproxy/v2.1.4/LICENSE"
+  },
+  "version": "2.1.4",
+  "architecture": {
+    "64bit": {
+      "url": "https://github.com/Shopify/toxiproxy/releases/download/v2.1.4/toxiproxy-server-windows-amd64.exe",
+      "hash": "2190b6d75570dc3b9bd5c026467c33b3f8811151a9022393666af0eaa6fda315"
+    }
+  },
+  "bin": [["toxiproxy-server-windows-amd64.exe", "toxiproxy.exe"],
+          ["toxiproxy-server-windows-amd64.exe", "toxiproxy"]]
+}