Add predictions for elimination matches

Currently, the application ignores the existence of elimination matches. This prevents us from using the application to predict match scores for future elimination matches. To enable this, we'll need to make the following modifications:

- Modify the TBA schedule importer to not ignore elimination matches
- Modify the CSV schedule importer and CSV schedule format to include elimination matches
- Modify get-match-statistics to accept non-integer arguments, recognize these as elimination matches, and correctly generate statistics for the matches

Locate the TBA schedule importer, the CSV schedule importer and format, and get-match-statistics. First trace how regular matches are imported and passed into statistics generation, then determine how elimination matches are represented in each path. Done means both importers retain elimination matches and get-match-statistics accepts and correctly processes their non-integer identifiers.

Written by the indexing model from the issue text.