Add LaunchBox clear logo provider to Extra Metadata Loader

[mjd4219]

Summary

• Adds LaunchBox as an additional Extra Metadata Loader clear-logo provider.
• Builds a local cache from LaunchBox Metadata.zip, filters GameImage entries to Clear Logo only, and resolves images through the LaunchBox image CDN.
• Adds a LaunchBox logo menu item plus an opt-in setting for automatic/library-update LaunchBox logo downloads.
• Keeps existing Steam, SteamGridDB, Google logo, YouTube/video, theme-control, manifest, and extension identity behavior intact.

[mjd4219]

Closing for now while the extension is manually tested and debugged. Will reopen/raise a new PR once functionality is verified.

[darklinkpower]

Hello, the Extra Metadata extension in the master branch is not in working state. Please target the emlCrashFix2025 branch, which is the release version, sorry for the confusion. The code in master is a non-working partial rewrite. Additionally, new localization strings only need to be added to the en_US.xaml file.

[mjd4219]

Thanks. I opened a new PR targeting emlCrashFix2025: #752.

I have also raised the same LaunchBox clear-logo work against master, as it seems to work locally from my testing: #751.