The extra browser panels would always create on startup due to the
visibility change. This fixes that by ensuring that this call blocks
signals, and ensures that the call only happens on first creation by the
user and not when the user is loading on startup.
In the view -> Docks menu, when a user first creates a custom browser
dock, the menu item associated with them used to hide/show them will be
unchecked in the menu by mistake. This ensures they're checked when
first created.
Allows the ability for users to add custom browser widget docks that
they can use for their third party services if they feel the need,
mostly as a convenience tool so they don't have to open extra browsers
alongside the program.
