fix: Updates bootstrap example

Fixes the group-by example and switches to attribute allow-clear
feat: Replaces clunky bootstrap col classes

Adds more targetable classes .ui-select-placeholder
.ui-select-match-text .ui-select-clear
fix: Disabled now affects the main toggle button
feat: Improved bootstrap template text overflow behaviour
fix: Improves evaluation of group-by expression

Allows grouping by nested properties and functions
Merge branch 'feature/improved-bootstrap-templates' into develop