Feature request: Reasonable timeout and error handling for external requests

[PhMemmel]

• In the case that the ocis instance is unavailable (network connectivity issues on client or ocis side), the requests need to have a reasonable timeout (not more than maybe 10s?).
• In addition to that if the timeout limit has been reached, there need to be a proper error handling that avoids freezing the file picker making it unavailable.

[individual-it]

IMO the timeout should be configurable