Bug fixes

Add search form protection
Bug fixes and other minor improvements

• Worked some minor issues
• View as exposed filters integration

The 1.4 release fixed #2822280 issue.

Changes since 8.x-1.3:

• #2999941 by chipway, riddhi.addweb: Update Dependencies to new Format in .info.yml

• Issue #3035473 by stefan.korn: Fixed less file syntax for [Media Hero Slider]

• Issue #3047326: Added support for link_attributes in menus.
• Issue #3047330: Fixed typo from .sass to .scss in comments and tips for which variable files to work on.

From the plan
- Added subtheme block config files
- Fixed subtheme inheritance (base theme no longer overrides subtheme styles)
- Some javascript cleanup (replace search icon path)
- Gulpfile adjustments for gulp 4.0
- Better documentation
- Adding starter sass files to subtheme for easy variable adjustments
- Removed redundant gulp dependencies