cmd/geth : Enhancing Negative Input for commission rate

[sifnoc]

Currently, Negative Input for setCommission like this.

build/bin/geth  manage-staking setCommissionRate \
    --datadir ./.pls.staking/operator1 \
    --rootchain.url ws://127.0.0.1:8546 \           
    --unlock 0x5e3230019fed7ab462e3ac277e7709b9b2716b4f  \
    --password pwd.pass   \
    --rootchain.sender 0x5e3230019fed7ab462e3ac277e7709b9b2716b4f  \
    -- -0.4

Cause CLI could not recognize with - operator as a minus. treat as starting flag.

And also, the negative commission rate output as following.

rootchain=0xd6662103d7Ffd6D44792d9866AfAD0Beef5d3c32 commissionRate=-0.010

User and Operator may mis reading as a positive rate In a terminal.

I suggest that using prefix "M" with commission rate input.

Expecting result.

build/bin/geth  manage-staking setCommissionRate M0.01 \
    --datadir ./.pls.staking/operator1 \
    --rootchain.url ws://127.0.0.1:8546 \           
    --unlock 0x5e3230019fed7ab462e3ac277e7709b9b2716b4f  \
    --password pwd.pass   \
    --rootchain.sender 0x5e3230019fed7ab462e3ac277e7709b9b2716b4f 

rootchain=0xd6662103d7Ffd6D44792d9866AfAD0Beef5d3c32 commissionRate=M0.010