Dropdown: Allow to pass "className" with a group as well

[dominikj111]

Describe the feature you would like to see added

I need to pass a specific className with the options group along with the "p-dropdown-item-group" class.
It is possible to do this with an item only.
https://codesandbox.io/s/primereact-dropdown-panel-width-yp9v59?file=/src/App.js

Is your feature request related to a problem?

I have first group without the label what causes to render additional white space on the start of the list of options.

Describe the solution you'd like

No response

Describe alternatives you have considered

No response

Additional context

No response

[melloware]

Isn't that just this: https://codesandbox.io/s/primereact-dropdown-panel-width-forked-zc2kw3

pt={{
            itemGroup: ({ context }) => ({
              className: "bg-primary"
            })
          }}

[dominikj111]

Sounds like that, but I would like to pass className in relation to specific item on same way as I'm doing when not using groups. So I need to pass it in the options structure.

[melloware]

Got it i think it just needs the extra data passed to it!

[melloware]

@dominikj111 please review my PR. Now it adds the optionGroupLabel to the context as well as adds the style empty if the label is empty.