Add screen rendering events for buttons

src/main/kotlin/moe/nea/firmament/events/HandledScreenForegroundEvent.kt

@@ -0,0 +1,10 @@
+package moe.nea.firmament.events
+
+import net.minecraft.client.gui.screen.ingame.HandledScreen
+
+data class HandledScreenForegroundEvent(
+    val screen: HandledScreen<*>,
+    val mouseX: Int, val mouseY: Int, val delta: Float
+) : FirmamentEvent() {
+    companion object : FirmamentEventBus<HandledScreenForegroundEvent>()
+}

src/main/kotlin/moe/nea/firmament/events/HandledScreenPushREIEvent.kt

@@ -0,0 +1,16 @@
+package moe.nea.firmament.events
+
+import me.shedaniel.math.Rectangle
+import net.minecraft.client.gui.screen.ingame.HandledScreen
+
+data class HandledScreenPushREIEvent(
+    val screen: HandledScreen<*>,
+    val rectangles: MutableList<Rectangle> = mutableListOf()
+) : FirmamentEvent() {
+
+    fun block(rectangle: Rectangle) {
+        rectangles.add(rectangle)
+    }
+
+    companion object : FirmamentEventBus<HandledScreenPushREIEvent>()
+}

src/main/kotlin/moe/nea/firmament/events/ScreenClickEvent.kt

@@ -0,0 +1,8 @@
+package moe.nea.firmament.events
+
+import net.minecraft.client.gui.screen.ingame.HandledScreen
+
+data class ScreenClickEvent(val screen: HandledScreen<*>, val mouseX: Double, val mouseY: Double, val button: Int) :
+    FirmamentEvent.Cancellable() {
+    companion object : FirmamentEventBus<ScreenClickEvent>()
+}