core: block destroyed contracts and restrict maximum contract updates

[AnnaShaleva]

Close #2458.

[codecov]

Codecov Report

Merging #2462 (ffdcdf4) into master (3c0ee9c) will increase coverage by 0.02%.
The diff coverage is 75.00%.

@@            Coverage Diff             @@
##           master    #2462      +/-   ##
==========================================
+ Coverage   85.10%   85.13%   +0.02%     
==========================================
  Files         291      291              
  Lines       36732    36742      +10     
==========================================
+ Hits        31262    31281      +19     
+ Misses       4155     4148       -7     
+ Partials     1315     1313       -2     

Impacted Files	Coverage Δ
pkg/services/oracle/network.go	75.86% <0.00%> (ø)
pkg/services/oracle/oracle.go	88.37% <ø> (ø)
pkg/core/native/management.go	92.50% <57.14%> (-0.59%)	⬇️
pkg/core/native/contract.go	100.00% <100.00%> (ø)
pkg/core/native/policy.go	91.46% <100.00%> (+0.08%)	⬆️
pkg/consensus/consensus.go	73.43% <0.00%> (+0.44%)	⬆️
pkg/core/transaction/transaction.go	87.45% <0.00%> (+1.52%)	⬆️
pkg/network/message.go	96.26% <0.00%> (+2.23%)	⬆️
pkg/network/capability/capability.go	75.00% <0.00%> (+5.76%)	⬆️

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