Update images in instance loading page (#23589)

...ent/app/instance-loading-page/img/bring-data-to-slack.png

...pp/instance-loading-page/img/click-charts-dive-deeper.png

...t/app/instance-loading-page/img/click-column-headings.png

...nd_client/app/instance-loading-page/img/metabase-logo.svg

..._client/app/instance-loading-page/img/no-sql-required.png

...rces/frontend_client/app/instance-loading-page/styles.css

resources/frontend_client/init.html

resources/frontend_client/inline_js/init.js