Test support for xls/xlsx

[sonalgoyal]

Build a new febrl test file in XLS/XLSX format and test it

[navinrathore]

The "spark-excel" library can support excel files in spark

<!-- https://mvnrepository.com/artifact/com.crealytics/spark-excel -->
<dependency>
	<groupId>com.crealytics</groupId>
	<artifactId>spark-excel_${scala.binary.version}</artifactId>
	<version>3.1.2_0.16.4</version>
</dependency>

The *.xls files have been successfully tested for reading. however, *.xlsx file reading is not successful. It does not give any clear message

WARN  zingg.client.Client - Apologies for this message. Zingg has encountered an error. Factory

Tested with both v1, v2 APIs for this library. The .xlsx file has been created with MS excel. Spark 3.1.2 has been used.

[sonalgoyal]

we can add the above library as jars and build an example with it.

[sonalgoyal]

@gnanaprakash-ravi can you try this? you can add the extra jars through zingg.conf (https://docs.zingg.ai/zingg/stepbystep/zingg-runtime-properties) and see if we can read and write xls. if so, please add the documentation on how to do so.