Prevent a user from switching to a custom network which fails

[oskarleonard]

What was the problem?

This PR resolves #5309

How was it solved?

Make sure our networkClient is set before making the request. This is to prevent race conditions.

How was it tested?

1. Switch from Betanet to Testnet
2. Expected: Show error in the dropdown
3. Do this a couple of times, switching between Betanet, Testnet and your locally added devnet
4. Expected: Should not get into a freeze state as in the issue.

[eniolam1000752]

There is also the issue of residual persisted network/application information lingering around the local storage even though they have been removed.

Below is a list of all the networks which I don't even see in my network list

[eniolam1000752]

• On editing a previously added custom network, the name on the selected network becomes empty.