c++20 Windows issue reproducers and possible fixes

[michael-baumann]

-C2065, constexpr parentState not visible from lamba, make it const -C2440, cannot convert from initializer list, add ctor

Only occurs with c++20, so enable this as well in the according CMakeLists

[codecov-commenter]

Codecov Report

Merging #177 (387dd6e) into master (589ad20) will increase coverage by 0.00%. The diff coverage is 100.00%.

:exclamation: Current head 387dd6e differs from pull request most recent head 34efb45. Consider uploading reports for the commit 34efb45 to get more accurate results

@@           Coverage Diff           @@
##           master     #177   +/-   ##
=======================================
  Coverage   97.76%   97.76%           
=======================================
  Files          79       80    +1     
  Lines        1117     1120    +3     
=======================================
+ Hits         1092     1095    +3     
  Misses         25       25           

Impacted Files	Coverage Δ
test/integration/dependency_injection.cpp	100.00% <100.00%> (ø)
...st/integration/exit_pseudo_states_with_history.cpp	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 589ad20...34efb45. Read the comment docs.

[erikzenker]

@michael-baumann Thank you for your contribution!