Add skin fixer

src/main/kotlin/moe/nea/firmament/features/FeatureManager.kt

@@ -25,6 +25,7 @@ import moe.nea.firmament.features.chat.ImagePreview
 import moe.nea.firmament.features.debug.DebugView
 import moe.nea.firmament.features.debug.DeveloperFeatures
 import moe.nea.firmament.features.fishing.FishingWarning
+import moe.nea.firmament.features.fixes.Fixes
 import moe.nea.firmament.features.inventory.CraftingOverlay
 import moe.nea.firmament.features.inventory.SaveCursorPosition
 import moe.nea.firmament.features.inventory.SlotLocking
@@ -60,6 +61,7 @@ object FeatureManager : DataHolder<FeatureManager.Config>(serializer(), "feature
             loadFeature(ImagePreview)
             loadFeature(SaveCursorPosition)
             loadFeature(CustomSkyBlockTextures)
+            loadFeature(Fixes)
             if (Firmament.DEBUG) {
                 loadFeature(DeveloperFeatures)
                 loadFeature(DebugView)

src/main/kotlin/moe/nea/firmament/features/fixes/Fixes.kt

@@ -0,0 +1,16 @@
+package moe.nea.firmament.features.fixes
+
+import moe.nea.firmament.features.FirmamentFeature
+import moe.nea.firmament.gui.config.ManagedConfig
+
+object Fixes : FirmamentFeature {
+    override val identifier: String
+        get() = "fixes"
+
+    object TConfig : ManagedConfig(identifier) {
+        val fixUnsignedPlayerSkins by toggle("player-skins") { true }
+    }
+
+    override fun onLoad() {
+    }
+}

src/main/kotlin/moe/nea/firmament/repo/ItemCache.kt

@@ -34,6 +34,7 @@ import kotlinx.coroutines.launch
 import net.minecraft.SharedConstants
 import net.minecraft.block.entity.SkullBlockEntity
 import net.minecraft.client.resource.language.I18n
+import net.minecraft.client.texture.PlayerSkinProvider
 import net.minecraft.datafixer.Schemas
 import net.minecraft.datafixer.TypeReferences
 import net.minecraft.item.ItemStack