add startup option to update votes for inactive objects in api nodes

[oxarbitrage]

User Story

From an open-explorer issue regarding the list of active committee_members and witnesses: bitshares/open-explorer#31

Initial discussion in the core: #803 (comment) is related as adding to the count of votes in inactive objects will impact latency of maint block.

Decided to make a startup option to count this objects so api nodes will want to have this enabled while block producers probably not.

Impacts
Describe which portion(s) of BitShares Core may be impacted by your request. Please tick at least one box.

• API (the application programming interface)
• Build (the build process or something prior to compiled code)
• CLI (the command line wallet)
• Deployment (the deployment process after building such as Docker, Travis, etc.)
• DEX (the Decentralized EXchange, market engine, etc.)
• P2P (the peer-to-peer network for transaction/block propagation)
• Performance (system or user efficiency, etc.)
• Protocol (the blockchain logic, consensus, validation, etc.)
• Security (the security of system or user data, etc.)
• UX (the User Experience)
• Other (please add below)
  witness_node command line startup and config file.

CORE TEAM TASK LIST

• Evaluate / Prioritize Feature Request
• Refine User Stories / Requirements
• Define Test Cases
• Design / Develop Solution
• Perform QA/Testing
• Update Documentation

[clockworkgr]

Although calculating the votes for ALL objects would be ideal, if it's too much of a performance issue, we should at least update the count for inactive ones to 0 to avoid misrepresentations like the one you encountered in open-explorer.

[abitmore]

Another option is to add a compile-time option, like the method used in #1099

• compile-time option will result in better performance;
• it's good to have all similar options at the same place.

I'll work in this direction.

[oxarbitrage]

closed by #1191