Make the Ocean API endpoint (and others) configurable

[GuybrushX]

Which feature is your request related to?

If the Ocean API is down the DEX isn't working anymore. This is very bad and could be very expensive as well.

Is your request related to a problem? Please describe.

During the recent market movements the DEX wasn't accessible anymore at all - it was stuck at "Loading..." for hours.

Describe the solution you'd like:

Implement the feature like it is done in the Light Wallet already: make critical endpoints configurable, mainly the Ocean API and others of they are required as well.

Describe alternatives you've considered:

Officially abandon the Desktop Wallet and provide guides on how to migrate to the Light Wallet

Additional context:

NA