refactor: improve ResourceData.kt

Old methods have been marked as deprecated, and will be removed in the future.

- ResourceData.kt was made an Iterable<File>, and the forEach method was removed in favor of Kotlin's forEach function. (no modifications required)
- The resolve method was deprecated in favor of a new operator getter function, which can be either called using get(path) or data[path]. This keeps backwards compatibility with the old get method.
- The getXmlEditor method was deprecated in favor of the new xmlEditor variable, which is a XmlFileHolder which has an operator getter which acts like an array. This is syntactically better.

src/test/kotlin/app/revanced/patcher/usage/resource/patch/ExampleResourcePatch.kt

@@ -18,8 +18,8 @@ import org.w3c.dom.Element
 @Version("0.0.1")
 class ExampleResourcePatch : ResourcePatch() {
     override fun execute(data: ResourceData): PatchResult {
-        data.getXmlEditor("AndroidManifest.xml").use { domFileEditor ->
-            val element = domFileEditor // regular DomFileEditor
+        data.xmlEditor["AndroidManifest.xml"].use { editor ->
+            val element = editor // regular DomFileEditor
                 .file
                 .getElementsByTagName("application")
                 .item(0) as Element