GravityView 2.22

* Added: Search Bar support for the [Chained Selects](https://www.gravityforms.com/add-ons/chained-selects/) field type
* Improved: Plugin updater script now supports auto-updates and better supports multisite installations
* Improved: If a View does not support joined forms, log as a notice, not an error
* Fixed: Merge Tag picker behavior when using Gravity Forms 2.6
* Fixed: Deleting a file when editing an entry as a non-administrator user on Gravity Forms 2.6.1 results in a server error
* Fixed: When The Events Calendar Pro plugin is active, Views became un-editable
* Tweak: Additional translation strings related to View editing

Note: We will be requiring Gravity Forms 2.5 and WordPress 5.3 in the near future; please upgrade!

__Developer Updates:__

* Added: Search URLs now support `input_{field ID}` formats as well as `filter_{field ID}`; the following will both be treated the same:
- `/view/example/?filter_3=SEARCH`
- `/view/example/?input_3=SEARCH`
* Added: In the admin, CSS classes are now added to the `body` tag based on Gravity Forms version. See `GravityView_Admin_Views::add_gf_version_css_class()`
* Modified: Allow non-admin users with "edit entry" permissions to delete uploaded files
* Updated: EDD_SL_Plugin_Updater script to version 1.9.1

* Added: Support for displaying WebP images
* Improved: Internal logging of notices and errors
* Fixed: Images hosted on Dropbox sometimes would not display properly on the Safari browser. Thanks, Kevin M. Dean!

__Developer Updates:__

* Added: `GravityView_Image::get_image_extensions()` static method to fetch full list of extension types interpreted as images by GravityView.
* Added: `webp` as a valid image extension

* Fixed: Empty values in search widget fields may return incorrect results

__Developer Updates:__

Added: `gravityview/search/ignore-empty-values` filter to control strict matching of empty field values