Rename ‘File a Bug’ to ‘Report an Issue’

This makes it more consistent with ‘Report an issue’ under View > Debug Log.

Not using ellipsis as menu item doesn’t require user confirmation:
https://stackoverflow.com/a/637708

_locales/en/messages.json

@@ -386,9 +386,9 @@
       "message": "Go to Support Page",
       "description": "Item under the Help menu, takes you to the support page"
     },
-    "fileABug": {
-      "message": "File a Bug",
-      "description": "Item under the Help menu, takes you to GitHub new issue form"
+    "menuReportIssue": {
+      "message": "Report an Issue",
+      "description": "Item under the Help menu, takes you to GitHub new issue form (title case)"
     },
     "aboutSignalDesktop": {
       "message": "About Signal Desktop",

app/menu.js

@@ -130,7 +130,7 @@ exports.createTemplate = (options, messages) => {
         click: openSupportPage,
       },
       {
-        label: messages.fileABug.message,
+        label: messages.menuReportIssue.message,
         click: openNewBugForm,
       },
       {

test/app/fixtures/menu-mac-os-setup.json

@@ -172,7 +172,7 @@
         "click": null
       },
       {
-        "label": "File a Bug",
+        "label": "Report an Issue",
         "click": null
       }
     ]

test/app/fixtures/menu-mac-os.json

@@ -159,7 +159,7 @@
         "click": null
       },
       {
-        "label": "File a Bug",
+        "label": "Report an Issue",
         "click": null
       }
     ]

test/app/fixtures/menu-windows-linux-setup.json

@@ -119,7 +119,7 @@
         "click": null
       },
       {
-        "label": "File a Bug",
+        "label": "Report an Issue",
         "click": null
       },
       {

test/app/fixtures/menu-windows-linux.json

@@ -108,7 +108,7 @@
         "click": null
       },
       {
-        "label": "File a Bug",
+        "label": "Report an Issue",
         "click": null
       },
       {