Add two tests for image compression, one failing deliberately atm

src/test/kotlin/org/briarproject/briar/desktop/attachment/media/ImageCompressorTest.kt

+/*
+ * Briar Desktop
+ * Copyright (C) 2021-2022 The Briar Project
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.briarproject.briar.desktop.attachment.media
+
+import java.net.URL
+import javax.imageio.ImageIO
+import kotlin.test.Test
+
+class ImageCompressorTest {
+
+    private val compressor = ImageCompressorImpl()
+
+    @Test
+    fun `can compress voronoi image`() {
+        // load image
+        val input = Thread.currentThread().contextClassLoader.getResourceAsStream("images/voronoi1.png")
+        val image = input.use {
+            ImageIO.read(input)
+        }
+        println("image size: ${image.width}x${image.height}")
+
+        // compress image
+        val compressed = compressor.compressImage(image)
+
+        // reload compressed image
+        val reloaded = compressed.use {
+            ImageIO.read(compressed)
+        }
+        println("image size: ${reloaded.width}x${reloaded.height}")
+    }
+
+    @Test
+    fun `can compress quasar`() {
+        // load image
+        val url = "https://upload.wikimedia.org/wikipedia/commons/3/38/Artist%27s_rendering_ULAS_J1120%2B0641.jpg"
+        val input = URL(url).openStream()
+        val image = input.use {
+            ImageIO.read(input)
+        }
+        println("image size: ${image.width}x${image.height}")
+
+        // compress image
+        val compressed = compressor.compressImage(image)
+
+        // reload compressed image
+        val reloaded = compressed.use {
+            ImageIO.read(compressed)
+        }
+        println("image size: ${reloaded.width}x${reloaded.height}")
+    }
+
+}