Default token space config

[willyogo]

As platform admins, we want to add the default token space config to the codebase and be able to easily update it.

AC:

1. Default token space config is added
2. Unclaimed Token Spaces use both the Theme, Tabs, and Fidgets from the default token config (related to Display Token Spaces when URL is visited #525)

[to-do: attach default fidget & theme config to this issue]

[willyogo]

hiporox will set up the initial default config for token spaces, but will just include the Pinned Cast fidget for now.

@sktbrd can implement the final default config when ready