Replicate javascript to process new endpoint

This is the JS that needs to be replicated https://git.drupalcode.org/project/sitewide_alert/-/blob/2.x/js/init.js?...

The way it works is that the block is just a div target, line 2 in the init.js targets that div and inserts the contents of the alerts found in the endpoint. Our catch is that we have three different targets, so our version of init.js will need to figure out from each item in the endpoint which div it needs to get thrown into.

Discussion from 5/15 meeting.

• Ideally the javascript would be set up in Sitewide Alert module as a Class that we then extend
• For the MVP, we're going to just Copy and Paste the javascript from the module into each of the three blocks
• One JS file pulls all alerts and then routes alerts to appropriate block of those three blocks