Config schema issues in config tests themselves

1. Making some exemptions in schema checking for things that are not or only partially schema covered *by design*.
2. Add a whole bunch of missing things for tested data structures in config_test.schema.yml.
3. Add missing schemas for config_collection_install_test and config_events_test.
4. Add config_test module as a test dependency to ConfigFileContentTest so we have the schema available.

Only one fail seems to be left locally in ConfigDependencyTest. That does not look trivial to me :/ Maybe I am overlooking something.

Ok CRUD test has some more stuff.

There are too many intricate details of how the tests test schema-less elements, so some config tests will *need* to be exempt from config schema checking to be able to stay sane.

Use config_test.schemaless in the tests where we do not want to exempt config_test.noschema from testing, so we can keep it exempt at other config tests while still testing the rest.

Finally the ConfigQueryTest was initializing the array as null, not an empty array. To fix that for schema, initialize as array.

Rerolled. Did not apply anymore due to #2363155: content_translation.settings config is not scalable.

Duh, rolled that wrong. Here is the right one.

We also don't need the config_test module in ConfigFileContentTest which was only added so we can provide schema, but the things tested there are crazy to provide schema for.

Reuploading for bot.

Thanks!