Add a warn flag when --netuid 0 is used for btcli hotkey swap

[nstankov-stkd]

Using something along the lines of

      /usr/local/bin/btcli wallet swap-hotkey "$SWAP_HOTKEY_NAME" --wallet-path="$HOME/verySecretPath" --wallet-name='cold' --wallet.hotkey hot --netuid "0" --network "$CHAIN_ENDPOINT" --yes

Has the unintended consequence of not porting over any child-hotkey mappings the original hotkey, registered on SN0, might have had.
Adding warnings to prevent users from doing that.

[thewhaleking]

This is nice to have:
Add warning and confirmation for wallet swap_hotkey --netuid 0 to prevent accidental misuse. Using --netuid 0 only swaps the hotkey on the root network (netuid 0) and does NOT move child hotkey delegation mappings. This is not a full swap across all subnets. Updated documentation and added comprehensive unit tests to clarify proper usage.

But should not go in the changelog as-is. The changelog is updated on release.

[thewhaleking]

Removed changelog in #673