Fix opacity on inline block style design

Add `ccm-block-edit-inline-active` to set opacity to 1 while in inline
edit mode for block style design
Merge branch 'fix_opacity_on_block_design' of https://github.com/mkly/concrete5-5.7.0 into mkly-fix_opacity_on_block_design
Merge branch 'develop' of github.com:concrete5/concrete5-5.7.0 into develop