Add test mode gas when invoking

[bettybao1209]

close neo-project/neo#2260

[superboyiii]

https://github.com/bettybao1209/neo-node/blob/a85b767e76a62a0343c1b276743f1b4199bd1041/neo-cli/CLI/MainService.cs#L488
Please change here like: using (ApplicationEngine engine = ApplicationEngine.Run(tx.Script, container: tx, gas:1010_00000000)), it was called by register candidates method straightly. This is what I need.

[bettybao1209]

Please change here like: using (ApplicationEngine engine = ApplicationEngine.Run(tx.Script, container: tx, gas:1010_00000000)), it was called by register candidates method straightly. This is what I need.

There are two ways to register a candidate, so I updated both the invoke and register candidate commands. Also, I have to add the TestModeGas in MakeTransaction method since it also runs the script. Please review again.

[bettybao1209]

Use comma to separate signers.

1. Insufficient gas (two signers + default gas):
   invoke 0xf61eebf573ea36593fd43aa150c055ad7906ab83 registerCandidate [{"type":"PublicKey","value":"03d922481a6190c0afdc200600abec944d5b588a6fe6ef9639cc28be3493319b0d"}] NaqFR6Qv3VM3XWLLqbuK6PwRi9uYGGDk1e NMbT8LVG9aLdKs3HBzf5LvV2XBqjjjjpeR,NUjGMLwcYZuhUSTeNcZSvYkrQRciAhnFET

2. succeed (+ 1010 gas) :
   invoke 0xf61eebf573ea36593fd43aa150c055ad7906ab83 registerCandidate [{"type":"PublicKey","value":"03d922481a6190c0afdc200600abec944d5b588a6fe6ef9639cc28be3493319b0d"}] NaqFR6Qv3VM3XWLLqbuK6PwRi9uYGGDk1e NMbT8LVG9aLdKs3HBzf5LvV2XBqjjjjpeR,NUjGMLwcYZuhUSTeNcZSvYkrQRciAhnFET 1010

[bettybao1209]

wait for #733