[MDEP-957] By default, don't report slf4j-simple as unused

[elharo]

slf4j-simple is a super common "unused" dependency because when slfj-api or slf4j-impl is included and slf4j-simple isn't, the application works just fine but prints an annoying log message to the console telling developers to add it.

SLF4J: No SLF4J providers were found.
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See https://www.slf4j.org/codes.html#noProviders for further details.

or

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See https://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

so devs deliberately add slf4j-simple to their dependencies just to shut up these warnings.

see https://www.slf4j.org/manual.html

[slawekjaranowski]

1. why not use a default option of parameter?
2. when user defined another ignores list it will be overridden ... maybe we need add it latter to be always ignored ...

[elharo]

A little later in the file I see this comment

    // defaultValue value on @Parameter - not work with Maven 3.2.5
    // When is set defaultValue always win, and there is no possibility to override by plugin configuration.

[slawekjaranowski]

also setting to something else will detect slf4j-simple again

[elharo]

I took this comment out. The doc generator will pick up the default value here and document it.

[michael-o]

No objection. @slawekjaranowski?