Remove FieldInitializer class

We don't need to track the class version and maxStack value: the
Library::remap will already have access to them (and always needs to, as
it has to fiddle with {Class,Field,Method}Nodes to actually move the
field).

Signed-off-by: Graham <gpe@openrs2.dev>

asm/src/main/java/dev/openrs2/asm/classpath/ExtendedRemapper.kt

@@ -1,9 +1,10 @@
 package dev.openrs2.asm.classpath
 
 import org.objectweb.asm.commons.Remapper
+import org.objectweb.asm.tree.AbstractInsnNode
 
 abstract class ExtendedRemapper : Remapper() {
-    open fun getFieldInitializer(owner: String, name: String, descriptor: String): FieldInitializer? {
+    open fun getFieldInitializer(owner: String, name: String, descriptor: String): List<AbstractInsnNode>? {
         return null
     }
 

asm/src/main/java/dev/openrs2/asm/classpath/FieldInitializer.kt

@@ -1,14 +0,0 @@
-package dev.openrs2.asm.classpath
-
-import dev.openrs2.asm.MemberRef
-import org.objectweb.asm.Opcodes
-import org.objectweb.asm.tree.AbstractInsnNode
-import org.objectweb.asm.tree.FieldInsnNode
-
-class FieldInitializer(val instructions: List<AbstractInsnNode>, val version: Int, val maxStack: Int) {
-    val dependencies = instructions.asSequence()
-        .filterIsInstance<FieldInsnNode>()
-        .filter { it.opcode == Opcodes.GETSTATIC }
-        .map(::MemberRef)
-        .toSet()
-}