Add tokenized version of o.o. to Stempel stopwords [LUCENE-8416]

The Stempel stopword list ( lucene-solr/lucene/analysis/stempel/src/resources/org/apache/lucene/analysis/pl/stopwords.txt ) contains "o.o." which is a good stopword (it's part of the abbreviation for "limited liability company", which is "[sp. z o.o.](https://en.wiktionary.org/wiki/sp._z_o.o.)". However, the standard tokenizer changes "o.o." to "o.o" so the stopword filter has no effect.

Add "o.o" to the stopword list. (It's probably okay to leave "o.o." in the list, though, in case a different tokenizer is used.)

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Migrated from [LUCENE-8416](https://issues.apache.org/jira/browse/LUCENE-8416) by Trey Jones, updated Sep 12 2018
Pull requests: https://github.com/apache/lucene-solr/pull/447

Open lucene-solr/lucene/analysis/stempel/src/resources/org/apache/lucene/analysis/pl/stopwords.txt and inspect the existing "o.o." entry alongside the Standard Tokenizer behavior described in the issue. Done means the tokenized "o.o" form is present so the stopword filter can match it, while the original entry may remain.

Written by the indexing model from the issue text.