Emdash source with visual editor image upload fix

Fixes:
1. media.ts: wrap placeholder generation in try-catch
2. toolbar.ts: check r.ok, display error message in popover

packages/plugins/marketplace-test/tsconfig.json

@@ -0,0 +1,9 @@
+{
+	"extends": "../tsconfig.base.json",
+	"compilerOptions": {
+		"rootDir": "src",
+		"outDir": "dist",
+		"strict": false
+	},
+	"include": ["src"]
+}