Refactor game mode scoring and win conditions

* Add overridable hooks for sunk/reaped ball handling and turn behavior.
* Implement default scoring and game-over messaging across game modes.
* Add pretty game mode names for win-condition messages.
* Update Free Ball, Last Ball, and Snooker modes to return win-condition messages.
* Move the reset button lookup to the scene root for multiplayer setup.
* Move camera controller scene to shared base UI. Move parts of it to new game_data UI node.
* Add commented test state generation for end-state testing.

scenes/ui_controls/game/data.gd

@@ -0,0 +1,33 @@
+extends Control
+
+
+@onready var player_lbl: Label  = $vbox/hbox/hbox/player_lbl
+@onready var active_lbl: Label  = $vbox/hbox/hbox/active_lbl
+@onready var reset_bttn: Button = $vbox/hbox/hbox2/reset_bttn
+
+
+func _ready() -> void:
+	setup_signals()
+	setup_multiplayer()
+
+	MessageBus.emit_local("update_active_lbl", null)
+
+
+func setup_signals() -> void:
+	MessageBus.subscribe("update_active_lbl", _on_update_active_lbl)
+
+func setup_multiplayer() -> void:
+	player_lbl.text = Globals.game_data.player_id
+
+	if not Globals.multiplayer_data.is_multiplayer_active: return
+
+	reset_bttn.pressed.disconnect(_on_reset_bttn_pressed)
+	reset_bttn.visible = false
+
+
+func _on_update_active_lbl() -> void:
+	active_lbl.visible = \
+	Globals.multiplayer_data.current_turn_player_id == multiplayer.get_unique_id()
+
+func _on_reset_bttn_pressed() -> void:
+	Globals.game_state.reload_scene.emit()