Use enwiki data set

[tonysun83]

This performance test loads the enwiki data set defined by
docs.file in the content-source.properties file.
DocMaker: https://lucene.apache.org/core/8_0_0/benchmark/org/apache/lucene/benchmark/byTask/feeds/DocMaker.html

parses the xml files and creates ready to be indexed documents. Any wikipedia dataset downloaded from https://dumps.wikimedia.org/enwiki/20190501/ is usable as long as it is specified correctly in the properties file.

We can override the getContentSource to use other content sources:
https://lucene.apache.org/core/7_3_1/benchmark/org/apache/lucene/benchmark/byTask/feeds/ContentSource.html
for different benchmarking needs.

I left the lucene-test-framework library intact in our pom.xml because there are older performance benchmarks that still rely on it. We should remove it once we fully transition over to the lucene benchmark data set

Next steps:

1. Use a different content source
2. Run queries with https://lucene.apache.org/core/7_4_0/benchmark/org/apache/lucene/benchmark/byTask/feeds/EnwikiQueryMaker.html