Use Storybook Globals API

[literalpie]

In storybook 8.3, the globals api was introduced. This seems like the perfect api to reduce the complexity of this addon.

A sketch of what I'm thinking:

• Make a new global called "addon-rtl"
  • I think this is a better name than "direction" since it's more clearly related to our addon
• Keep the existing icon button in the toolbar, and call setGlobal when it's toggled. Should we disable the button when a global is set at the story level, like the built-in global toolbar items?
• For compatibility, we should try to continue to respect url params, events, and story parameters. Maybe keep track of "eventsState" and give that priority over other state. I don't think we should do anything special to support the case where both story parameters and globals are provided.

[literalpie]

I think trying to keep compatibility with parameters will be annoying. We should just jump to 2.0 even though 1.0 isn't that old.

• We will disable the button when storyGlobals is set
• The global will be called addonRtl
• We can respect URL params, but also the globals api has its own version of url params
• Events can still work the same as before

WIP branch