Use current protocol version in MockEpochManager

[jancionear]

KeyValueRuntime creates a MockEpochManager which returns epoch infos with protocol versions set to 1.
The fact that some tests run with protocol version 1, but still use structs from the current protocol version messes up some checks that I'm trying to add.
Let's use the current protocol version in the mock epoch info. Running things with protocol version 1 isn't very realisitic anyway.

I had to fix one test which tests the "maintenance windows" feature - the maintenance windows (heights where a specific validator is not a block or chunk producer) were different in protocol version 1, I think this is because the validator assignment algorithm has changed. I think it's better to test the latest assignment algorithm.

I checked the new validator assignments by adding manual prints in the get_maintenance_windows function.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 71.51%. Comparing base (cd319ac) to head (8931a7f).
Report is 4 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #12304      +/-   ##
==========================================
- Coverage   71.55%   71.51%   -0.05%     
==========================================
  Files         836      836              
  Lines      168170   168288     +118     
  Branches   168170   168288     +118     
==========================================
+ Hits       120335   120349      +14     
- Misses      42585    42683      +98     
- Partials     5250     5256       +6     

Flag	Coverage Δ
backward-compatibility	0.16% <0.00%> (-0.01%)	⬇️
db-migration	0.16% <0.00%> (-0.01%)	⬇️
genesis-check	1.24% <0.00%> (-0.01%)	⬇️
integration-tests	38.78% <100.00%> (-0.05%)	⬇️
linux	71.15% <100.00%> (-0.05%)	⬇️
linux-nightly	71.10% <100.00%> (-0.03%)	⬇️
macos	54.27% <100.00%> (-0.05%)	⬇️
pytests	1.55% <0.00%> (-0.01%)	⬇️
sanity-checks	1.36% <0.00%> (-0.01%)	⬇️
unittests	65.27% <100.00%> (-0.05%)	⬇️
upgradability	0.21% <0.00%> (-0.01%)	⬇️

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