Switching node chain types

[flomang]

The user should be able to open a mainnet wallet, close it, and open a textnet wallet. If the wallet is set to use the embedded node the embedded node should shutdown the mainnet node and start a testnet node on another thread. This sometimes fails and the testnet wallet is not able to communicate with the embedded node.

I'm noticing these traces when I switch chains:

grin_wallet_api::owner - Wallet state updater failed with error: ClientCallback("Error calling get_unspent_outputs: Request error: Cannot make request: error sending request for url (https://127.0.0.1:3413/v2/foreign): operation timed out")
20221213 10:24:58.359 ERROR grin_wallet_impls::node_clients::http - Error calling get_tip: Request error: Cannot make request: error sending request for url (https://127.0.0.1:13413/v2/foreign): error trying to connect: tcp connect error: Connection refused (os error 61)