Update doxygen settings

[lukaszstolarczuk]

• set proper version of project displayed in doxygen's docs
• fix class index view (only one column)
• make doc is verbose now

v1.5 preview, after fixes: https://lukaszstolarczuk.github.io/libpmemobj-cpp/v1.5/doxygen/classes.html

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This change is 

[codecov]

Codecov Report

Merging #858 into stable-1.5 will decrease coverage by 0.34%.
The diff coverage is n/a.

@@              Coverage Diff               @@
##           stable-1.5     #858      +/-   ##
==============================================
- Coverage       90.77%   90.43%   -0.35%     
==============================================
  Files              26       26              
  Lines            1052     1025      -27     
==============================================
- Hits              955      927      -28     
- Misses             97       98       +1     

Flag	Coverage Δ
#tests_clang_debug_cpp17	61.93% <ø> (-29.53%)	⬇️
#tests_clang_release	61.46% <ø> (-28.86%)	⬇️
#tests_gcc_debug	93.40% <ø> (ø)
#tests_gcc_release_cpp17	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
include/libpmemobj++/detail/conversions.hpp	80.00% <0.00%> (-20.00%)	⬇️
include/libpmemobj++/make_persistent.hpp	76.19% <0.00%> (-14.29%)	⬇️
include/libpmemobj++/make_persistent_array.hpp	83.33% <0.00%> (-5.35%)	⬇️
include/libpmemobj++/condition_variable.hpp	82.66% <0.00%> (-2.67%)	⬇️
include/libpmemobj++/transaction.hpp	87.34% <0.00%> (-2.54%)	⬇️
include/libpmemobj++/detail/life.hpp	92.30% <0.00%> (-1.81%)	⬇️
...lude/libpmemobj++/make_persistent_array_atomic.hpp	94.73% <0.00%> (-0.51%)	⬇️
include/libpmemobj++/experimental/array.hpp	100.00% <0.00%> (ø)
.../libpmemobj++/experimental/contiguous_iterator.hpp	100.00% <0.00%> (ø)
include/libpmemobj++/persistent_ptr.hpp	97.19% <0.00%> (+1.74%)	⬆️
... and 3 more

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Reviewed 1 of 1 files at r1.
Reviewable status: complete! all files reviewed, all discussions resolved