An attempt to fix #2796

The dokkaHtmlMultiModule started failing after the change in Gradle: gradle/gradle@7d9d6c4#diff-8d6d587bb7323c4c8105f5616986da4d67c575f8f7fb576071e58587e17a6878 where a new constructor appeared.

1. Changed AbstractTaskDependency to DefaultTaskDependency.
   The logic behind this: the message https://github.com/gradle/gradle/blob/ab07117466b9a28de41c1ec85a3fb6f4c61abbcd/subprojects/core/src/main/java/org/gradle/api/internal/AbstractTask.java#L102 that AbstactTask should be replaced with DefaultTask. So I apply the same for AbstractTaskDependency and DefaultTaskDependency. even they are both are in *internal* package. But we try to override method public TaskDependencyInternal getTaskDependencies() that returns an interface from the same *internal* package.
2. I remove custom logic in visitDependencies from TaskDependencyInternalWithAdditions and delegate it to the default implementation of the DefaultTaskDependency. It seems to contain the same. And for that, I inject tasks inside the DefaultTaskDependency.
3. There are 2 ways to delegate tasks to the DefaultTaskDependency according to documentation (javadoc): in the constructor and with the add function. The way with the constructor is even recommended from a performance point of view.
   But it requires adding a dependency to Google common collections (full guava?) and I tried to avoid it.