Feature/zzhang/rpc tx

[lispc]

• user can pledge gas for others
• gas contract use ram correctly

[codecov]

Codecov Report

Merging #438 into develop will increase coverage by 0.03%.
The diff coverage is 8.55%.

@@             Coverage Diff             @@
##           develop     #438      +/-   ##
===========================================
+ Coverage     23.4%   23.44%   +0.03%     
===========================================
  Files           93       92       -1     
  Lines        13186    13220      +34     
===========================================
+ Hits          3086     3099      +13     
- Misses        9700     9722      +22     
+ Partials       400      399       -1

Impacted Files	Coverage Δ
vm/database/db.go	100% <ø> (ø)	⬆️
vm/host/info.go	4.34% <0%> (ø)	⬆️
vm/host/teller.go	13.33% <0%> (ø)	⬆️
rpc/apis.go	4.81% <0%> (-0.21%)	⬇️
vm/isolator.go	0% <0%> (ø)	⬆️
vm/host/gas_manager.go	2.18% <0%> (-9.82%)	⬇️
verifier/simulator.go	0% <0%> (ø)	⬆️
common/fixed.go	56% <66.66%> (+7.03%)	⬆️
ilog/logger.go	73.8% <0%> (+1.19%)	⬆️