Fixing Fortnite update/install info instead of breaking.

[Stormanzanii]

Summary

Fixes Fortnite installations and updates through Heroic when Legendary reports a selective download size that differs significantly from Fortnite's full manifest size.

Previously, this difference could cause Fortnite's progress percentage, download graph, download speed, and disk speed to stop updating or display incorrect values..

Changes

• Uses Fortnite's effective download size reported by Legendary for progress calculations
• Keeps download percentage, download speed, disk speed, transferred bytes, and ETA updated.
• Validates and clamps progress percentages to prevent invalid values.
• Resets stale progress before starting a Fortnite install or update.

Testing

• Successfully installed Fortnite through Heroic.
• Confirmed Fortnite's progress percentage and speed information update during installation.
• Passed TypeScript, Prettier, and whitespace checks.

Checklist

• Tested the feature and it's working on a current and clean install.
• Tested the main App features and they are still working on a current and clean install. (Login, Install, Play, Uninstall, Move games, etc.)
• Created / Updated Tests (If necessary)
• Created / Updated documentation (If necessary)

[flavioislima]

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

[Stormanzanii]

I have read the CLA Document and I hereby sign the CLA