Improve metrics output

リンクされたワークフロー実行に表示されている github/codeql-action/analyze の出力から始め、メトリクステーブルとベースラインメッセージがどのように生成されるかを追跡します。issue ではソースファイルもテストも指定されていません。完了の条件は、メトリクス行で結果を区別する列が維持され、メトリクスセクションが視覚的に分離され、ベースラインの文が一度だけ表示され、さらにその挙動が CodeQL CLI と Java queries のどちらに属するのかが明確になっていることです。

Version

CodeQL CLI: 2.8.5
CodeQL action: 1.1.8 (according to CODEQL_ACTION_VERSION environment variable)

Description

Currently (at least for Java projects) the metrics table printed at the end of github/codeql-action/analyze contains the same metric name multiple times, e.g.:

|                          Metric                          | Value |
+----------------------------------------------------------+-------+
| Total lines of code in the database                      |  9668 |
| External libraries                                       |  1458 |
| External libraries                                       |    28 |
| External libraries                                       |     9 |
| External libraries                                       |     7 |
| External libraries                                       |     6 |
| External libraries                                       |     1 |
| Supported sinks in external libraries                    |     7 |
| Supported sinks in external libraries                    |     6 |
| Supported sinks in external libraries                    |     4 |
| Supported sinks in external libraries                    |     2 |
| Supported sinks in external libraries                    |     1 |
| Supported sinks in external libraries                    |     1 |
| Supported sinks in external libraries                    |     1 |
| Supported sinks in external libraries                    |     1 |
| Supported flow steps in external libraries               |    82 |
| Supported flow steps in external libraries               |    42 |
| Supported flow steps in external libraries               |    36 |
| Supported flow steps in external libraries               |    30 |
| Supported flow steps in external libraries               |    25 |
...

(workflow run)

The issue might be that these queries have multiple result columns, but the table here only seems to contain the usages count, discarding the other columns. Maybe the underlying issue is therefore caused by CodeQL CLI or by the Java queries.

Additionally it might be good to add an empty line in front of "Analysis produced the following metric data:" (to separate it more clearly from the previous table). And also the "Counted a baseline of ..." sentence seems to be printed twice (workflow run).