Rewrite plugin, use filenames in lockfile

fixtures/projects/dependency/classifier/groovy/build.gradle

@@ -0,0 +1,11 @@
+plugins {
+    id 'java'
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    implementation 'com.badlogicgames.gdx:gdx-platform:1.9.9:natives-desktop'
+}

fixtures/projects/dependency/classifier/kotlin/build.gradle.kts

@@ -0,0 +1,11 @@
+plugins {
+    java
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    implementation("com.badlogicgames.gdx:gdx-platform:1.9.9:natives-desktop")
+}