fix(NcAppSidebar): remove always hover styles from actions in non-compact mode

[ShGKme]

☑️ Resolves

• Fix https://github.com/nextcloud-libraries/nextcloud-vue/issues/5363
• Remove unneeded background with hover-like styles from NcAction in NcAppSidebar for non-compact mode without figure
• Make this button always looks the same
• Small refactoring — remove other non-needed styles from actions. NcActions has these styles already.

🖼️ Screenshots

🏚️ Before	🏡 After

🏁 Checklist

• [ ] ⛑️ Tests are included or are not applicable
• [x] 📘 Component documentation has been extended, updated or is not applicable
• [x] 3️⃣ Backport to next requested with a Vue 3 upgrade

[ShGKme]

/backport to next

[susnux]

I tried to fix the screenshots but this is a mess... Wish we have a command for it...