feat(dashmate): check for DKG before stopping node

[pshenmic]

Issue being fixed or feature implemented

#1648

When node is participating in DKG exchange process, it is dangerous to restart the node, because it can result to the PoSe ban.
Recently, Dash Core v20.1 was released that include a quorum dkginfo RPC call, that shows if nodes is exchanging DKG or will in the upcoming blocks.

This PR adds a check for that before stopping node.

What was done?

• Added a check for masternodes for a potential DKG exchange happen soon during dashmate stop command (reduce PoSE bans)
• Implemented an --safe flag for dashmate stop command, that will wait until DKG window passes and flawlessly stops your node

How Has This Been Tested?

Locally with dashmate in testnet and local setups

Breaking Changes

No

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have added "!" to the title and described breaking changes in the corresponding section if my code contains any
• I have made corresponding changes to the documentation if needed

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone

[shumkov]

👍

[qwizzie]

Nice job.