Schema Compare extension (#4974)

* extension now working

* fix diff editor title disappearing and remove border from source and target name boxes

* redoing a bunch of stuff that disappeared after rebasing

* add images and add to extensions.ts

* moving a few changes to the right place after rebase

* formatting

* update toolbar svgs

* addressing comments

* add return types

* Adding PR comments

* Adding light and dark theme icons

* Fixing the diff editor title for dark theme

extensions/schema-compare/tsconfig.json

@@ -0,0 +1,20 @@
+{
+    "compileOnSave": true,
+    "compilerOptions": {
+        "module": "commonjs",
+        "target": "es6",
+        "outDir": "./out",
+        "lib": [
+            "es6",
+            "es2015.promise"
+        ],
+        "sourceMap": true,
+        "emitDecoratorMetadata": true,
+        "experimentalDecorators": true,
+        "moduleResolution": "node",
+        "declaration": false
+    },
+    "exclude": [
+        "node_modules"
+    ]
+}