Added OOP approach to some boilerplate code currently implemented

@DieGurke,as I don't want to interfere with your branch at all, I only
added the absolute minimum that should be mergeable without conflict.
I leave the rest of the implementation (usage in ChatScene, ChatControl
and referencing in FXML) up to you.
There's no way in hell I'll risk your wrath...

client/src/main/java/envoy/client/ui/custom/ProfilePicImageView.java

@@ -0,0 +1,62 @@
+package envoy.client.ui.custom;
+
+import javafx.scene.image.Image;
+import javafx.scene.image.ImageView;
+import javafx.scene.shape.Rectangle;
+
+/**
+ * Displays the profile picture of a user using the superior method of OOP
+ * instead of boilerplate code.
+ * <p>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>ProfilePicImageView.java</strong><br>
+ * Created: <strong>30.07.2020</strong><br>
+ *
+ * @author Leon Hofmeister
+ * @since Envoy Client v0.2-beta
+ */
+public final class ProfilePicImageView extends ImageView {
+
+	/**
+	 * Creates a new {@code ProfilePicImageView} without a default image.
+	 *
+	 * @since Envoy Client v0.2-beta
+	 */
+	public ProfilePicImageView() { this(null); }
+
+	/**
+	 * Creates a new {@code ProfilePicImageView}.
+	 *
+	 * @param image the image to display
+	 * @since Envoy Client v0.2-beta
+	 */
+	public ProfilePicImageView(Image image) { this(image, 40); }
+
+	/**
+	 * Creates a new {@code ProfilePicImageView}.
+	 *
+	 * @param image           the image to display
+	 * @param sizeAndRounding the size and rounding for a circular
+	 *                        {@code ProfilePicImageView}
+	 * @since Envoy Client v0.2-beta
+	 */
+	public ProfilePicImageView(Image image, double sizeAndRounding) { this(image, sizeAndRounding, sizeAndRounding); }
+
+	/**
+	 * Creates a new {@code ProfilePicImageView}.
+	 *
+	 * @param image    the image to display
+	 * @param size     the size of this {@code ProfilePicImageView}
+	 * @param rounding how rounded this {@code ProfilePicImageView} should be
+	 * @since Envoy Client v0.2-beta
+	 */
+	public ProfilePicImageView(Image image, double size, double rounding) {
+		super(image);
+		final var clip = new Rectangle();
+		clip.setWidth(size);
+		clip.setHeight(size);
+		clip.setArcHeight(rounding);
+		clip.setArcWidth(rounding);
+		setClip(clip);
+	}
+}

client/src/main/java/envoy/client/ui/custom/package-info.java

@@ -0,0 +1,14 @@
+/**
+ * This package stores custom components for use in JavaFX.
+ * These components are also expected to be used via FXML.
+ * <p>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>package-info.java</strong><br>
+ * Created: <strong>30.07.2020</strong><br>
+ *
+ * @author Leon Hofmeister
+ * @author Maximilian K&auml;fer
+ * @author Kai S. K. Engelbart
+ * @since Envoy Client v0.2-beta
+ */
+package envoy.client.ui.custom;

client/src/main/java/module-info.java

@@ -20,4 +20,5 @@ module envoy {
 
 	opens envoy.client.ui to javafx.graphics, javafx.fxml;
 	opens envoy.client.ui.controller to javafx.graphics, javafx.fxml;
+	opens envoy.client.ui.custom to javafx.graphics, javafx.fxml;
 }