Allow mainchain to switch to different service url

[oskarleonard]

What was the problem?

This PR resolves #5357

How was it solved?

• Check if provided custom network URL has valid ServiceURLs before letting the user save the new network
• When switching to a new network, check if serviceURL is OK, might be serviceURL nr 2, in that case choose URL nr 2
• When opening the app, check if serviceURL is OK, might be serviceURL nr 2, in that case choose URL nr 2

How was it tested?

Prerequisite

You need to modify the endpoint returning serviceURLs, this we can do by modifying the response in docker, replace serviceURLs with:

[
  {
    "http": "http://localcrash:8080",
    "ws": "ws://localcrash:9901",
  },
  {
    "http": "http://127.0.0.1:9901",
    "ws": "ws://127.0.0.1:9901",
  }
]

The first item in that array should have a http that crashes.

Please refer to the below video.

Screen.Recording.2023-10-27.at.11.41.39.mov

Test the scenarios in "How was it solved?"