Switch most remaining extensions to use esbuild

Just 3 left:

- git and github. These are doing weird stuff with d.ts imports and const enums

- github-authentication  which has some tricky path mapping stuff

extensions/ipynb/tsconfig.browser.json

@@ -0,0 +1,10 @@
+{
+	"extends": "./tsconfig.json",
+	"compilerOptions": {},
+	"exclude": [
+		"./src/test/**"
+	],
+	"files": [
+		"./src/ipynbMain.browser.ts"
+	]
+}