iotdb时间戳精度支持微秒、纳秒，但是udf最小时间单位只有毫秒

以udf中的re_sample为例，当iotdb时间戳精度设置为us时, re_sample()中参数‘every’设置为100ms时，实际重采样频率为100微秒，有单位错位问题，请教下这个问题如何解决？

Start with the UDF re_sample entry point and trace how the every parameter is interpreted when IoTDB timestamps use microsecond or nanosecond precision. Reproduce the reported case with every=100ms and microsecond timestamps, then establish the expected resampling interval and verify that the implementation uses the correct unit.

Scritto dal modello di indicizzazione a partire dal testo della issue.