Replace/rewrite fc::uint128 with boost::multiprecision for better performance

[abitmore]

User Story

@pmconrad mentioned in #1083 (comment):

One conclusion I have drawn is that boost::multiprecision performs significantly better than fc::uint128

fc::uint128 is in the code for serialization. For better performance, we could avoid using it for routine computation, E.G.

bitshares-core/libraries/chain/asset_object.cpp

Lines 40 to 44 in 58c0c49

	fc::uint128 volume = current_supply.value + force_settled_volume.value;
	volume *= options.maximum_force_settlement_volume;
	volume /= GRAPHENE_100_PERCENT;
	return volume.to_uint64();
	}

and more (try search).

One potential approach is to rewrite fc::uint128 (perhaps with boost::multiprecision) so it will have both better performance and compatible serialization. Another approach would be modifying individual code, replace fc::uint128 with boost::multiprecision when possible.

This is a sub-task of #982.

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)

Additional Context (optional)
Add any other context about your request here.

CORE TEAM TASK LIST

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

[pmconrad]

Also part of #1584

[pmconrad]

Merged with #1789