Performance improvements

Created by: noClaps

• Use largest resolution copy of proPic. This is 200x200 so it should still be large enough to not look too blurry.
• Avoid unnecessary requests to Discuit. If there is found proPic URL, then don't wait for the fetch() to fail to return the default favicon.
• Avoid additional map() step when making communities array.
• Use Bun.nanoseconds() for more precise time measurement.