Support large log file visualization

[13Ducks]

In order to support large file visualization, we need to bypass the Lambda input limit size (6MB) which was constraining us. To do this, the visualizer client is changed to use the new API routes.

1. client posts to /get-upload-link: gets a pre-signed POST URL to upload the file to S3
2. client uses URL to upload file to S3 so Lambda can access it directly
3. client posts to /upload-complete: runs Lambda and returns visualizer URL