*: adapt state-dependent block producing time

[AnnaShaleva]

Ref. nspcc-dev/neo-go#3745.

Let's firstly finalize nspcc-dev/neo-go#3835 before the merge, because we might want to add height parameter to WithSecondsPerBlock setting (to me it's not needed, but still may be considered).

[codecov]

Codecov Report

Attention: Patch coverage is 76.47059% with 4 lines in your changes missing coverage. Please review.

Project coverage is 57.66%. Comparing base (6a1eac8) to head (b5dd36e).
Report is 11 commits behind head on master.

Files with missing lines	Patch %	Lines
internal/consensus/consensus.go	0.00%	3 Missing ⚠️
config.go	66.66%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #147      +/-   ##
==========================================
- Coverage   57.86%   57.66%   -0.20%     
==========================================
  Files          33       33              
  Lines        2283     2277       -6     
==========================================
- Hits         1321     1313       -8     
- Misses        873      875       +2     
  Partials       89       89              

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[roman-khimov]

height parameter

But why if we're always running dbft for the next block?

[AnnaShaleva]

But why if we're always running dbft for the next block?

As I said, I don't think it's needed, because every dependent service is OK with the current behaviour. I just wanted to hear your opinion.

[AnnaShaleva]

@roman-khimov, ready for review, it's the final implementation, we can merge it.