SOGS progress events

[slimbuck]

This PR:

• adds a progress option to http get which will send progress updates
• adds the progress event to Img's _loadImageBitmap implementation
• collate the progress events and fire them on the parent SOGS asset

Notes

• combineProgress functionality can possibly be made available outside of sogs

[Copilot]

Pull Request Overview

This PR implements progress tracking functionality for SOGS (Splat Object Graphics System) assets by adding progress event handling to HTTP requests and propagating these events through the asset loading pipeline.

• Adds progress event support to the HTTP GET method with optional progress callback
• Integrates progress tracking into the image bitmap loading process
• Implements progress event aggregation across multiple assets for SOGS parsing

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/platform/net/http.js	Adds progress option parameter and event handling to HTTP GET requests
src/framework/parsers/texture/img.js	Updates _loadImageBitmap to accept asset parameter and pass it as progress handler
src/framework/parsers/sogs.js	Implements combineProgress utility to aggregate progress events from multiple texture assets