* Add toggle control to sidebar in editor.
Adds a visibility toggle in the Mini Cart block's sidebar editor
settings for the block price.
* Update name of hasVisiblePrice attrubite.
Adjusts the name of the hasVisiblePrice attribute to hasHiddenPrice.
This seems a bit easier to reason about, where we can set the default
state of the visibility toggle to 'off'.
* Add conditional price rendering to server side.
Since this is a dynamic block, need to add the condidional attribute
state to the server-side render callback.
* Add price visibility setting to block frontend.
We need to prevent pricec from rendering when hidden setting is active
after the JS kicks in on the frontend (i.e., when the Mini Cart is
interacted with by the user).
* Fix logic error in frontend rendering conditional.
* Add unit tests for both show/hide price states.