Add slippage protection to "swap" and "transfer"

[Jackalgirl]

My previous issue, #644 , was closed, as part of #758 , which was closed due to potential risks inherent in the PR. I'd like to reopen it; please comment with a non-technical (meaning: layperson's) explanation of why these features can't be added to move and transfer if the problem is with the requested feature (as opposed to having been a problem with the way the closed PR was coded), thanks!

Currently, the options for protecting against sandwich attacks/front-running that are in place for btcli st add:

--tolerance,--rate-tolerance
--safe-staking,--safe
--no-safe-staking,--unsafe

are not available for swap or transfer. Both swap and transfer allow for moving of stakes across subnets, which results in an unstake-and-stake operation in the back-end, which means that there is an opportunity for the operation to be attacked.

Although it may be that the default 5% tolerance automatically applies, users should be able to increase the tolerance (or even decrease it, if they want to be more risky).

I recommend that you add these three options to swap and transfer so that those commands are consistent with add.

[ibraheem-abe]

This will be applicable when we get support for the new extrinsics on chain