Use a different CLI flag when specifying shares to reclaim from an escrow

[tjanez]

SUMMARY

Currently, the oasis-node stake account gen_reclaim_escrow subcommand uses the --stake.amount flag for specifying the amount of shares to reclaim from an escrow:

https://github.com/oasislabs/oasis-core/blob/6ccac659d9bcf885dd2240c469bf5757ca19ee56/go/oasis-node/cmd/stake/account.go#L207

This is different from what one would expect by reading subcommand's --help:

https://github.com/oasislabs/oasis-core/blob/6ccac659d9bcf885dd2240c469bf5757ca19ee56/go/oasis-node/cmd/stake/account.go#L207

or reading the current version of the Operator docs:

We reclaim 3000 escrowed tokens by generating the reclaim escrow transaction:

oasis-node stake account gen_reclaim_escrow \
  ... trimmed ...
  --stake.transaction.amount 3000 \
  ... trimmed ...

ISSUE TYPE

• Bug

ADDITIONAL INFORMATION

In the future, we might also add the ability to specify the amount of tokens (base units) to reclaim from an escrow and compute the number of shares automatically.

However, it is not possible to know how much the shares will be worth before the debonding period expires since any slashing could change shares' price.