Execute self-nomination transactions automatically

[majecty]

We have a tool "auto-self-nominate" written in TypeScript.

We should run "auto-self-nominate" in a separate process from the CodeChain node. Since managing several processes costs a lot, running the same logic in the CodeChain process will reduce the overall managing cost.

[MSNTCS]

@majecty
We need to have the same logic of cron-jobs/auto-self-nominate/src/index.ts. Run a procedure like send that checks whether the address is banned or in the jail, makes the address as a candidate, deposits then sends a self Nominate transaction n times where n is intervals. Therefore, we need some parameters to add to codechain/codechain.yml. These parameters are as follows:

• account-address
• passphrase
• default-metadata
• target-deposit
• interval

[majecty]

We need some prefixes. The current argument names are too general.

My suggestion(You can suggest better names).

• defualt-metadata -> self-nomination-metadata
• target-deposit -> self-nomination-target-deposit
• interval -> self-nomination-interval

Since CodeChain receives the validator address as engine-signer we don't need to receive it as account-address. Since CodeChain uses a password file to use a private key we don't need to use the passphrase argument.

[MSNTCS]

A new thread is designed to send auto self-nomination transactions. A node should enable the enable-auto-self-nomination argument in order to run the thread and add new metadata, deposit, and interval for the new nomination. The thread checks whether the node is not jailed, is not banned and is valid to be a candidate then sends a self-nomination transaction.