CLI: Allow multiple vote accounts

[aoikurokawa]

• Modified increase-validator-stake to accept multiple vote_account and amount arguments

 cargo r --bin spl-stake-pool -- \
    --program-id DPoo15wWDqpPJJtS2MUZ49aRxqz5ZaaJCJP4z8bLuib \
    --url ~~~ \
    increase-validator-stake 
    --pool JitoY5pcAxWX6iyP2QdFwTznGb8A99PRCUCVVxB46WZ \
    --vote-account 23AoPQc3EPkfLWb14cKiWNahh1H9rtb3UBk8gWseohjF \
    --vote-account i7NyKBMJCA9bLM2nsGyAGCKHECuR2L5eh4GqFciuwNT 
    --amount 5 \
    --amount 5

[joncinque]

Thanks for your contribution. To be honest, I would prefer to not land a change like this, since a command like --vote-account X --amount Y --vote-account Z --amount A just looks too easy to mess up.

Instead, I'd recommend that people write a bash script to call increase-validator-stake multiple times.

Is there a particular motivation for this change not served by a script?

[aoikurokawa]

Thanks!
Might be better to write script like you mentioned rather than having complicated command line arguments.
Let me close this PR!