Add support for additional attribute passing to Dropdown component

[serickson-curology]

Updating the dropdown component to allow for more flexible use in the consuming library. Basically I am removing the explicit option for aria-label and replacing it with support for optional ...rest attributes. Had to update the docs and snapshot to go along with these changes.

[LilCare]

I'm definitely not an expert on component libraries, but it seems to me that we would want it to have a discrete number of possible attributes and values. Just curious: do you know what the best practice is here?

[LilCare]

Just curious: Are we fine with any attribute? Or do we want to hold onto a list of accepted values? We could then update to validate ...rest and reject any unknown attributes.

[serickson-curology]

I would tend to agree on being restrictive on which attributes we allow, but this is a pattern that currently exists in the deployed version of radiance-ui (In the button component, for instance.) and so I went with this solution for passing through more attributes without ballooning the parameter list.

I think it would be interesting to look into a pattern that allows for a bit more control on what is allowed through, but for an internal convenience library I don't know how much benefit we would actually get from it if it requires much of a rework.