### Godot version

4.2 RC2

### System information

Any

### Issue description

AnimationMixer separates the accuracy of how discrete keys are retrieved when seeking between internal seeking and external seeking. FYI: https://github.com/godotengine/godot/pull/80708.

Since AnimationPlayer currently treats everything as an internal seek, so it needs to propagate the external seek information.

### Steps to reproduce

Seek AnimationTrackEditor

### Minimal reproduction project

[gd_anim_unittest_1.zip](https://github.com/godotengine/godot/files/13492063/gd_anim_unittest_1.zip)

playback_queue.clear();
}
void AnimationPlayer::play_backwards(const StringName &p_name, double p_custom_blend) {
	play(p_name, p_custom_blend, -1, true);
}
void AnimationPlayer::play(const StringName &p_name, double p_custom_blend, float p_custom_scale, bool p_from_end) {
	StringName name = p_name;
	if (String(name) == "") {
		name = playback.assigned;
	}
	ERR_FAIL_COND_MSG(!animation_set.has(name), vformat("Animation not found: %s.", name));
	Playback &c = playback;
	if (c.current.from) {
		double blend_time = 0.0;
		
		BlendKey bk;
		bk.from = c.current.from->name;
		bk.to = name;
		if (p_custom_blend >= 0) {
			blend_time = p_custom_blend;
		} else if (blend_times.has(bk)) {
			blend_time = blend_times[bk];
		} else {
			bk.from = "*";