remove old water_bomb_model, put shaders into /assets/

assets/shaders/interactivity_outline.gdshader

@@ -0,0 +1,14 @@
+shader_type spatial;
+render_mode blend_mix, cull_front, unshaded;
+
+uniform vec4 color : source_color = vec4(1,0,0,1);
+uniform float size : hint_range(1.0, 1.5, 0.01) = 1.05;
+
+void vertex() {
+	VERTEX *= size;
+}
+
+void fragment() {
+	ALBEDO = color.rgb;
+	ALPHA = color.a;
+}