Add support for File entities and full Views integration

Use the appropriate field definition label for some simpler base field definitions.

Following the #2955078: Track file/image fields → issue being merged, the newly introduced File field plugin will need addressing so that it doesn't include duplicate entity usage references. It'd still be nice to include the ability to exclude "Thumbnails" from being referenced when the "Track referencing base fields" is enabled.

Would this also make it so that files will be marked temporary when the Entity Usage module says that there are no more uses? That's what I think should happen if the site has $config['file.settings']['make_unused_managed_files_temporary'] = TRUE;

Here is a reroll against 2.0-beta17

Sorry, ignore the last comment. something went wrong with the reroll... Here is the correct one.

Re-roll against 2.0-beta23

Re-roll against 2.0-beta23