Return null in place of filtering Safe overviews

[iamacook]

Description

We gracefully handle chains with throw when fetching Safe overviews. We do this in order to not block the UI should a chain-specific Transaction Service be misconfigured, etc.

Currently, errorneous chains are filtered out and there is no feedback given to the user. We should, instead, return null instead in a similar fashion to our v2 owner endpoint.

Requirements

• Rename current controller to v1
• Mark current method as deprecated
• Create v2 controller with new method

Additional information

After completion of this, a migration task should be added for clients to tackle.