a11y: Replace ButtonMultiAction with dropdown menu component

[rak-phillip]

Bulkable actions follow the dropdown menu pattern and can utilize the dropdown menu component.

Details

Actions are condensed down into a single ActionDropdown when there is not enough space on a page to display all bulkable table actions in a single row. This dropdown contains a special implementation that does not take into account accessibility or keyboard interactions. This should be replaced with a common dropdown component.

Acceptance criteria

• Custom ActionDropdown implementation is replaced with the Dropdown Menu component
• ActionDropdown has keyboard interactions that are consistent with other dropdown menus in Dashboard
• ActionDropdown does not regress in terms on content that it displays and when it is rendered

Screenshots

[richard-cox]

To confirm, is this for all widths? When there's adequate space we show individual buttons, when there's not we show the dropdown button instead.

Note there's functionality in there to show custom info regarding how many rows the bulk action will be applied to. Should be straight forward to take over to a common component, but just something to validate once done.

[rak-phillip]

To confirm, is this for all widths? When there's adequate space we show individual buttons, when there's not we show the dropdown button instead.

There is no intent to change page behavior; this should only be applicable where the dropdown button is currently used.