### 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)

delta = next_pos - cd.pos; 
		} break;
		case Animation::LOOP_LINEAR: {
			if (next_pos < 0 && cd.pos >= 0) {
				looped_flag = Animation::LOOPED_FLAG_START;
			}
			if (next_pos > len && cd.pos <= len) {
				looped_flag = Animation::LOOPED_FLAG_END;
			}
			next_pos = Math::fposmod(next_pos, (double)len);
		} break;
		case Animation::LOOP_PINGPONG: {
			if (next_pos < 0 && cd.pos >= 0) {
				cd.speed_scale *= -1.0;
				looped_flag = Animation::LOOPED_FLAG_START;
			}
			if (next_pos > len && cd.pos <= len) {
				cd.speed_scale *= -1.0;
				looped_flag = Animation::LOOPED_FLAG_END;
			}
			next_pos = Math::pingpong(next_pos, (double)len);
		} break;
		default:
			break;
	}
	double prev_pos = cd.pos; 
	cd.pos = next_pos;
	
	if (p_is_current) {
		if (cd.from->animation->get_loop_mode() == Animation::LOOP_NONE) {