Add calling scripthash check to native nep5 transfers

[roman-khimov]

Problem

It's impossible to transfer native assets from contract's address. And we have nasty old #924.

Solution

Add caller check to transfer and deal with script hash getters.

[codecov]

Codecov Report

Merging #1180 into master will increase coverage by 0.04%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##           master    #1180      +/-   ##
==========================================
+ Coverage   66.71%   66.75%   +0.04%     
==========================================
  Files         198      198              
  Lines       16802    16787      -15     
==========================================
- Hits        11210    11207       -3     
+ Misses       4995     4983      -12     
  Partials      597      597              

Impacted Files	Coverage Δ
pkg/core/interop/context.go	100.00% <ø> (ø)
pkg/core/native/native_neo.go	35.78% <0.00%> (+0.47%)	⬆️
pkg/core/native/native_nep5.go	71.02% <42.85%> (-0.18%)	⬇️
pkg/core/interop/runtime/witness.go	40.35% <50.00%> (ø)
pkg/core/interops.go	100.00% <100.00%> (ø)
pkg/core/native/policy.go	70.58% <100.00%> (-0.46%)	⬇️
pkg/vm/vm.go	88.30% <0.00%> (+0.38%)	⬆️
pkg/rpc/client/wsclient.go	84.56% <0.00%> (+1.34%)	⬆️

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