chore: Allow to provide props to the storybook iFrame

chore: Allow to provide props to the storybook iFrame

This allows to pass arguments to the storybook iFrame (well, except title) which will be passed to the iFrame in a semi-colon / colon separated format.

The arguments need to be prefixed with args-. So for example:

<story-viewer args-string="test" :args-bool="true" :args-num="5">

will pass:

{string: 'test', bool: true, num: 5}

to storybook.

Re #1203 (closed)