Make having a default action optional
Add an option to not use a default option and the dropbutton element. When not using a default option, a label is used that triggers a popover for choosing the block to add.
Closes #3157440
Add an option to not use a default option and the dropbutton element. When not using a default option, a label is used that triggers a popover for choosing the block to add.
Closes #3157440