### 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)

AnimationMixer::_animation_removed(p_name, p_library);
	StringName name = p_library == StringName() ? p_name : StringName(String(p_library) + "/" + String(p_name));
	if (!animation_set.has(name)) {
		return; 
	}
	_animation_set_cache_update();
	
	List<BlendKey> to_erase;
	for (const KeyValue<BlendKey, double> &E : blend_times) {
		BlendKey bk = E.key;
		if (bk.from == name || bk.to == name) {
			to_erase.push_back(bk);
		}
	}
	while (to_erase.size()) {
		blend_times.erase(to_erase.front()->get());
		to_erase.pop_front();
	}
}
void AnimationPlayer::_rename_animation(const StringName &p_from_name, const StringName &p_to_name) {