Improve element listing by introducing a view similar to admin/content

Problem/Motivation

Currently, the list of pagedesigner elements is created via EntityListBuilder. This offers only limited customizations and does not support filtering and sorting. A view provides a more flexible and powerful option.

Proposed resolution

Replace the list created by EntityListBuilder by a view, adding filters and sorting options.
The view provided will include an additional column (children) and allows filtering by type, publishing status and delete status.

Remaining tasks

- Create view configuration for installation/update
- Create update hook to deploy the view on existing installations

User interface changes

- The existing list under 'admin/content/pagedesigner_element' will be replaced by the view.
- The link under 'admin/content' will have a higher weight, moving it behind the files and media links

API changes

- Link definitions to the route entity.pagedesigner_element.collection are moved to the view.
- Collection route url has changed to 'admin/content/pagedesigner_elements'