Update to iOS 26 design

[jurajhilje]

Description

Build the IVPN iOS app with the new iOS 26 SDK to adopt the new interface found in the latest platform releases - iOS 26 and iPadOS 26.

Resources

https://developer.apple.com/documentation/TechnologyOverviews/adopting-liquid-glass
https://developer.apple.com/design/new-design-gallery/
https://developer.apple.com/design/resources/