add requires static java.sql to picocli module-info

[remkop]

In order to generate modular javadoc (#1298), the picocli module info needs this line:

requires static java.sql;

Because we have {@link java.sql.Types} in the CommandLine.java javadoc.
Without that requires statement, we get a "reference not found" error:

C:\Users\remko\IdeaProjects\picocli3\build\tmp\modules\info.picocli\picocli\CommandLine.java:3923: error: reference not found
         * in {@link java.sql.Types java.sql.Types} to the {@code int} value of these constants, but any other {@code int} fields should
                     ^