Frontend: Detect and warn user about unstable RPCs

[GabrielBuragev]

Issue Desription

Sometimes, the RPCs that are being used by our users are very unstable (delay in events/state updates, slow responses etc.). While most of the users use the official RPCs provided by the networks, there are cases when users use custom or third-party providers which are unstable.
We need to find a way to determine if the user is using an unstable one and show a warning message.

Acceptance Criteria

• Find a way to analyze and detect unstable RPCs
• Add a warning message and suggest possible options for stable RPCs