Products Onboarding: Update banner design with design review feedback

[rachelmcr]

Requested design changes from the design review:

• Add top/bottom borders to the banner
• Add a dismiss button
• Pre-load the product list when the banner is displayed (to avoid the skeleton loading animation on the Products tab)

Internal ref: p1667526735377029/1667415621.047949-slack-C0354HSNUJH

[peril-woocommerce]

	Fails
🚫	Please add a type label to this issue. e.g. 'type: enhancement'
🚫	Please add a feature label to this issue. e.g. 'feature: stats'

Generated by 🚫 dangerJS

[rachelmcr]

Pre-load the product list when the banner is displayed (to avoid the skeleton loading animation on the Products tab)

That behavior is related to how we sync the product list when the Products tab is first loaded, and I’m not coming up with any good solutions for adjusting that behavior in this scenario. We'll skip this change for now and can revisit it later on if needed. (Discussion: p1667573323126999/1667557384.565989-slack-C02KUCFCSFP)