[core] Make bucketed append table write initial lighter

[JingsongLi]

Purpose

In the past, we had to forcefully assign sequenceNumbers to the append table of bucketed, which made it very difficult to initialize the bucket table during write operations, even in write only mode.

We have modified it to only compare the file creation time to avoid difficulties in writing initialization.

Tests

• AppendOnlySimpleTableTest.testBucketedAppendTableWriteWithInit
• AppendOnlySimpleTableTest.testBucketedAppendTableWriteNoInit

API and Format

Documentation

[JingsongLi]

Only works when bucket-append-ordered is false.