Add Swift Package Manager support

[a1573595]

Hello,

Flutter is migrating to Swift Package Manager. Please also update your dependencies and keep an eye on Coinbase services for new SDK versions.

• reown_appkit 1.8.3 dependence coinbase_wallet_sdk 1.0.10
• reown_appkit 1.8.3 dependence reown_core 1.3.8
• reown_core 1.3.8 dependence flutter_secure_storage 9.2.4

[linear]

APKTN-709