js: Replace underscore with lodash and remove it from globals.

Tweaked by tabbott to bump PROVISION_VERSION.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

static/js/click_handlers.js

@@ -1,3 +1,4 @@
+const _ = require("lodash");
 // You won't find every click handler here, but it's a good place to start!
 
 const render_buddy_list_tooltip = require("../templates/buddy_list_tooltip.hbs");