Add warning for LNDHub users with balances over a certain amount

[kaloudis]

It gets a bit irresponsible to have a significant amount of sats in an LNDhub account. Users should perhaps get an extra warning in their balance pane if they hit a certain threshold.

At what level should it trigger though? 1M sats? 5M sats?

[myxmaster]

Since BlueWallet shut down its custodial LNDHub Service, I think we can close this, although it was a nice idea.

LNDHub still exists, but Zeus cannot know what funding source people are using (could be their own node).

[kaloudis]

Redundant now with the custodial warning added in https://github.com/ZeusLN/zeus/pull/2084