[CALCITE-6812] Support base64 and unbase64 functions for Hive #14728

Job	Run time
Windows (JDK 8)	16m 59s
Windows (JDK 21)	15m 36s
Windows (JDK 17)	16m 14s
Linux (JDK 8, oldest Guava, America/New_York Timezone)	11m 5s
Linux (JDK 11, Pacific/Chatham Timezone)	10m 29s
Linux (JDK 8, latest Guava, America/New_York Timezone)	12m 16s
Linux (JDK 21)	10m 0s
Linux (JDK 17)	10m 9s
Linux (JDK 11, Avatica main)	12m 29s
Linux (JDK 23)	10m 14s
macOS (JDK 21)	43m 23s
CheckerFramework (JDK 11)	11m 16s
CheckerFramework (JDK 11, oldest Guava)	10m 49s
ErrorProne (JDK 11, latest Guava)	4m 15s
Druid Tests	6m 49s
Linux (JDK 8) Slow Tests	0s
	3h 22m 3s

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