Resolve type mismatches and dependency conflicts

[aniketambore]

This PR addresses compatibility issues and build errors in the project, including:

• BigInt and int Type Mismatches: Resolved compile-time errors where BigInt types were incompatible with int parameters and vice-versa
• Dependency Conflict Resolution: Updated bdk_flutter as suggested by @i5hi in https://github.com/SatoshiPortal/bullbitcoin-mobile/issues/332#issuecomment-2452067966
• Downgraded share_plus to prevent further conflicts and it's usage in logger.dart
• Addressed several adjustments introduced by this version of bdk_flutter

These changes successfully allow the app to build from the source, fully resolving issue #332

[i5hi]

Thanks @aniketambore