Refactor project structure and update dependencies

Removed old database-related implementations (`Database`, `Migrations`, and `Main`) and replaced them with a new focus on MIDI message handling. Updated project metadata, introduced multiplatform `MidiMessage` classes, and added publication/CI setup for Maven compatibility.

src/commonMain/kotlin/nl/astraeus/midi/message/MidiMessage.kt

@@ -0,0 +1,42 @@
+package nl.astraeus.midi.message
+
+import nl.astraeus.tba.DataType
+import nl.astraeus.tba.MutableByteArrayHandler
+import nl.astraeus.tba.SlicedByteArray
+import nl.astraeus.tba.Type
+import nl.astraeus.tba.TypedByteArray
+import nl.astraeus.tba.blob
+import nl.astraeus.tba.double
+import nl.astraeus.tba.long
+
+class MidiMessage() : TypedByteArray(
+  Type("type", DataType.LONG),
+  Type("generated", DataType.DOUBLE),
+  Type("playTime", DataType.DOUBLE),
+  Type("midi", DataType.BLOB, 240),
+) {
+  var type by long("type")
+  var generated by double("generated")
+  var playTime by double("playTime")
+  var midi by blob("data")
+
+  init {
+    this.type = MidiMessageTypes.MIDI_DATA.typeId
+  }
+
+
+  constructor(data: ByteArray): this() {
+    check(data.size == definition.size) {
+      "Invalid data size: ${data.size} != ${definition.size}"
+    }
+
+    this.data = MutableByteArrayHandler(data)
+  }
+
+  constructor(playTime: Double, midi: ByteArray): this() {
+    this.generated = getCurrentTime()
+    this.playTime = playTime
+    this.midi = SlicedByteArray(midi)
+  }
+
+}