Improvements for Entry selection dialog - Finding turtles on turtles in a sea of entries

[humandevs]

Suggestions:

1. Allow Custom Views in Entry field Entry selection dialog box:
   Would need to be able to specify which Custom Views make sense for a specific Entry field.

2. Allow entry types that can't be selected for an entry field to be shown in the Entry selection dialog box.

3. Allow setting a section structure to collapse children by default in the view.

4. Advanced Search for fields not included in the default Entries selection dialog:
   Allowing this to happen in an explicit Advanced Search box would make this more clear by providing a 'search fields' button instead of a 'View' button (with effectively the same functionality), and avoid the performance impact unless required to search those fields.

Background: I usually want to sort Entries by name in the Entries section, but when selecting Entries in an Entry field I want to sort by dateUpdated by default.

Also, we have a Folder entry type that's just for organizing blocks into structures), which we don't want people to be able to select, but we want to show in the Entry selection dialog box else it's confusing seeing nested children without their parent entry (which we don't want to allow to actually add to the Entry field).

Also, when a large number of entries exist in one section, it can cause the section to take a very long time to load. Loading just 'parent' entry types and then allowing someone to expand those parent/folders to display their children would greatly speed up rendering, like a normal file system.

Finally, content authors get confused by the View button, not understanding it defines what fields will be returned on a search. In addition, in sections with a lot of entries, it can get very slow to load all of the fields a user may want to search. A button in the Filter flyout for 'select fields to search' that opens up the View list would be helpful here, or just an Advanced Search dialog with both. Or even a note that indicates 'only columns selected in the View menu will be searched'.