Fix configuration schema issues in block content (indirectly link and field test) modules

Fixes for the fails:

1. The test view had a wrong field key, should be fields.

2. The block content translation test encounters content_translation.settings, which is impossible to provide schema for. See #2363155: content_translation.settings config is not scalable. To make these pass, we need to provide an ignore schema. I also removed the schema assert from ContentTranslationSettingsTest.php in favor of the strict checking test option.

3. The block tests use test_field types and link fields respectively and schemas were missing for those.

In #2183983-74: Find hidden configuration schema issues @Berdir removed the cached data setting, which is indeed not referenced anywhere. Also fixing the default value for the test field.

Patch did not apply anymore. Rerolled. Also moved schema ignore fix to the checker. I should have remembered we don't have iteration support on ignore.

Resolving that PHP fatal by not invoking the method I am removing :)

Field settings schema keys were restructured in #2370305: Refactor field type configuration schemas for DX, easier to find errors, changed for those. Also found link_type field setting on links that I previously missed for some reason.

Rerolled due to #2316909: Revisit all built-in test/default views configuration in core.

Marked #2358263: Adding missing configuration schema for views blocks a duplicate because the same fails can be reproduced here and they are covered by making DisplayBlockTest strict on config schema.

Incorporated the fixes from there. Also trying to remove the fields in the test blocks because there are no link_to_node title fields in views_test_data (no title field even!).

This is starting to get a bit unwieldy as the test views that are imported from views_test also expose their problems here... Anyway, we can get going with fixing those fails so long as there is an end in sight :D Fixing fails from testbot related to missing plugin_id's (no typing for schema on test fields).

So the fails here are due to the views wizard. Duh. Opened #2381973: View wizard creates 'invalid' views out of the box, missing plugin_ids, insecure permissions. Postponing on that one.

#2381973: View wizard creates 'invalid' views out of the box, missing plugin_ids, insecure permissions landed. This needs a reroll.

Rerolled.

We should place blocks with label and not title, see docs and code of drupalPlaceBlock.

Note sure anymore that the test views were related, let's test without them. Will incorporate the fixes to #2325269: Test and fix views in test_views directories against their configuration schema unless required here. Should make reviewing the changes easier.

Was a bit carried away with aiming for simplicity :D We do need the test views fixes.

Reuploading #25 to avoid any confusion.

Yay, thanks!