feat: add manage collectibles feature

[ryanml]

Description

Implements a feature to manage the display of a user's nft's per: https://ava-labs.atlassian.net/browse/CP-9039

Changes

1. Added new view for managing collectibles
2. Updated settings handlers to accommodate the new allowlist

Testing

Verify that the three AC's specified in the story work correctly

Screenshots:

Checklist for the author

Tick each of them when done or if not applicable.

• I've covered new/modified business logic with Jest test cases.
• I've tested the changes myself before sending it to code review and QA.

[ryanml]

I thought about just using the tokensVisibility structure in the SettingsState, as it could be used with some adjustments to the typing of the parameters the handlers receive, but I thought it made sense to have a separation of concerns here.

[ryanml]

I need to confirm what these should be