Provide Run Selection button in Editor Title Menu (#2224)

* Provide Run Selection button in Editor Title Menu

This commit adds a editor title menu button for the
`powershell.RunSelection` command in the primary navigation group, and
a custom `play` icon based on ones from the
https://github.com/microsoft/vscode-icons repo. This shows the button
in the visible part of the menu when a PowerShell file is open.

Author: James Pogran

package.json

@@ -161,10 +161,23 @@
         },
         "category": "PowerShell"
       },
+      {
+        "command": "workbench.action.debug.start",
+        "title": "Run",
+        "category": "PowerShell",
+        "icon": {
+          "light": "resources/light/run.svg",
+          "dark": "resources/dark/run.svg"
+        }
+      },
       {
         "command": "PowerShell.RunSelection",
         "title": "Run Selection",
-        "category": "PowerShell"
+        "category": "PowerShell",
+        "icon": {
+          "light": "resources/light/play.svg",
+          "dark": "resources/dark/play.svg"
+        }
       },
       {
         "command": "PowerShell.RestartSession",
@@ -260,6 +273,18 @@
           "group": "2_powershell"
         }
       ],
+      "editor/title": [
+        {
+          "when": "resourceLangId == powershell",
+          "command": "workbench.action.debug.start",
+          "group": "navigation@100"
+        },
+        {
+          "when": "resourceLangId == powershell",
+          "command": "PowerShell.RunSelection",
+          "group": "navigation@101"
+        }
+      ],
       "editor/title/context": [
         {
           "when": "resourceFilename =~ /\\.tests\\.ps1$/i",