Add a tour for the ECA settings page

I've pushed a first draft for the tour tip content. I tried to mind the tour text standards defined here: https://www.drupal.org/docs/develop/user-interface-standards/tour-text-s → ... . the first unfocused tour tip describing the whole page is therefore intentionally without a selector and unfocused. some descriptions seem apparent but it has to be kept in mind that screen reader users dont have the extra visual context and information. there are a few open questions:

1. the labels for the last four tour tips are kind of long and more identical with the labels of the four checkboxes but i had no better idea for a clear wording. :/

2. one question about the last checkbox Newly added field configuration per bundle. from my understanding the other dependencies are checked on model save. but except the newly added the fourth checkbox is identical with the third. does that mean when the fourth checkbox is checked the dependencies is already checked when set in the model instead of later on on save?

3. and any feedback is welcome in regards of word smithing and details that have to be communicated.

Added some comments to the MR to improve the wording a bit and to address the questions in comment #8.

Moving to the separate module.

jurgenhaas → closed merge request !286