Simplify JavadocStyleCheck: remove functionality for missing package-info Javadoc

[rnveach]

Identified at #7416 item 1,

https://checkstyle.org/config_javadoc.html#JavadocStyle

We are attempting to trim back JavadocStyleCheck to help with a conversion to AbstractJavadocCheck. The first thing is to remove functionality that is identified as already being available in other checks.

Ensure package-info.java has a Javadoc.
is a duplicate of MissingJavadocPackage (Since 8.22).

This will remove this functionality and guide users on how to migrate their check.
https://www.baeldung.com/java-package-info
https://stackoverflow.com/questions/22095487/why-is-package-info-java-useful

========

Migration Notes

Users will have to add MissingJavadocPackage to their configuration, if it is not there already. No other options are needed.

Old Config Example:

<module name="Checker">
    <module name="TreeWalker">
        <module name="JavadocStyle"/>
    </module>
</module>

Migrated Config Example:

<module name="Checker">
    <module name="TreeWalker">
        <module name="JavadocStyle"/>
        <module name="MissingJavadocPackage"/>
    </module>
</module>

attention: javadoc.missing is removed from JavadocStyle module.

[nrmancuso]

Closed via #12521