Improve Button UI

[rann143]

• Suggest to mimic native apps a bit more in terms of familiar navigation patterns such as giving the tabs labels, like "Home" underneath the icon. ✅ Completed
• Text buttons could be bigger (hit area)
• icon buttons darker for easier visibility and interaction. ✅ Completed
• Examples:
  • Search icon button (to be darker), ✅ Completed
  • Artist Name text button on Player screen (text buttons bigger).