Time Travel for Qbeast-Spark!

[Jiaweihu08]

Add time-traveling feature to qbeast-spark:

// Time travel using version
val df = spark.read.format("qbeast").option("versionAsOf", "1984").load(tablePath)
val df = spark.sql("SELECT * FROM myCatalog.tableName VERSION AS OF 1984")

// Time travel using timestamp
val df = spark.read.format("qbeast").option("timestampAsOf", "1844-10-15").load(tablePath)
val df = spark.sql("SELECT * FROM myCatalog.tableName TIMESTAMP AS OF '1844-10-15'")