Improve/Optimize Coil Usage

[OxygenCobalt]

This PR fixes a variety of issues with how coil is used in the app:

• All ImageLoader instances have been replaced with a single App-Wide loader, as is recommended by the Coil Documentation. This improves efficiency and memory usage since bitmaps can be shared across the app. Most of the shared configuration [Such as the error icon] have been moved to here.
• Replaced most of the custom ImageRequest instances with the stock ImageView.load method.
• Instead of using a blocking call to get a Bitmap and then passing that to coil, the cover URI is now directly passed to Coil, which then loads it to the ImageView asynchronously. This greatly increases efficiency.
• Used Coil in the MediaMetadataCompat & Notification instances [Previously they used blocking calls and didn't share bitmap data with the rest of the app].
• Removed all IO co-routines involved with music loading since Coil already uses them.
• Enabled bitmap pooling, decreasing memory usage since bitmaps can be reused.
• Disabled automatic disc-caching, which decreases app size over time.
• Removed redundant state modifiers [E.G sIsCovers instead of just goPreference.isCovers]

Overall, this makes image loading both more maintainable and less error-prone compared to before. The most major API change is probably that the createNotification is now async, requiring an onDone lambda instead of returning the value directly. Other than that this preserves most of the normal architecture. Feel free to raise any concerns with my change.

[enricocid]

Thanks :)