This splits the bookmarks submodule into a seperate file, to make it easier to maintain (like how the search module was previously split out in #5697).
This also refactors bookmarks to require a new force option, to be more explicit about overriding existing bookmarks.
Add `preConfig`, which acts like `extraConfig`, but placed before
`settings`. This will allow to overwrite settings in `preConfig`,
using `settings` option.