Verify contents of LICENSE and NOTICE files [LUCENE-9249]

Based on question in Slack, it sounds like somebody needs to take a look at our LICENSE and NOTICE files for both Lucene and Solr to make sure that we are including the right things (and only what is necessary).

For reference: http://www.apache.org/dev/licensing-howto.html#overview-of-files

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Migrated from [LUCENE-9249](https://issues.apache.org/jira/browse/LUCENE-9249) by Mike Drob (@madrob), updated Mar 04 2020

Review the LICENSE and NOTICE files for both Lucene and Solr, then compare them with the Apache licensing how-to linked in the issue. Identify whether required items are present and unnecessary items are absent; done means any needed file updates are agreed and made.

Written by the indexing model from the issue text.