Bump Fuel to 3.0.0-alpha04

[Rimusolamus]

Updated Fuel HTTP library from 2.3.1 to 3.0.0-alpha04. It's a pretty big update - they rewrote everything for Kotlin Multiplatform.

Why we need this upgrade:
Old Fuel causes Kotlin version conflicts that break the build if project is based on new Kotlin.
The old Fuel 2.3.1 pulls in ancient Kotlin dependencies (like Kotlin 1.4.10) that conflict with modern Kotlin versions.
Fuel 3.0.0-alpha04 is built for Kotlin 2.0+ and uses modern kotlinx libraries, so everything stays in sync.

What changed?

Dependencies:

• Fuel 2.3.1 → 3.0.0-alpha04
• Removed fuel-android and fuel-coroutines (they're now built-in)

Code:
Just one file changed: File.kt

• New imports: fuel.* instead of com.github.kittinunf.fuel.*
• Switched from FuelManager to Fuel singleton
• httpLoader can be customizable using OkHttpClient
• Changed how we fetch data: .awaitByteArray() → .source.readByteArray()
• Added try-catch for better error handling

Testing:
I tried to run all existing sample apps and all seem to be good.

Heads up
This is an alpha version, so it's still being actively developed.
But it works fine for our use case (just downloading files from URLs).