Fix images on "Managing API Keys"

[Blargian]

Fix for images on Managing API Keys

Request:
https://clickhouse-inc.slack.com/archives/C03A9B0H05T/p1740698291246759

Summary

• updates screenshot to be better resolution and up to date
• moves styling of images from global styling to docs page and sets the max-width on the page itself

Checklist

• Delete items not relevant to your PR
• URL changes should add a redirect to the old URL via https://github.com/ClickHouse/clickhouse-docs/blob/main/docusaurus.config.js
• If adding a new integration page, also add an entry to the integrations list here: https://github.com/ClickHouse/clickhouse-docs/blob/main/docs/integrations/index.mdx