Fixes incorrect work of DataFrame with VBufferColumn when number of e…

[asmirnov82]

Fixes #6850

1) fixes max capacity calculation 2) fixes amount of required buffers calculation 3) fixes indexing

[asmirnov82]

@JakeRadMSFT

[codecov[bot]]

Codecov Report

Merging #6851 (b91e4f5) into main (7fe293d) will increase coverage by 0.61%. Report is 2 commits behind head on main. The diff coverage is 79.71%.

@@            Coverage Diff             @@
##             main    #6851      +/-   ##
==========================================
+ Coverage   69.03%   69.65%   +0.61%     
==========================================
  Files        1237     1237              
  Lines      253612   247617    -5995     
  Branches    26571    25436    -1135     
==========================================
- Hits       175092   172466    -2626     
+ Misses      71567    68536    -3031     
+ Partials     6953     6615     -338     

Flag	Coverage Δ
Debug	69.65% <79.71%> (+0.61%)	:arrow_up:
production	64.20% <68.18%> (+0.60%)	:arrow_up:
test	88.89% <100.00%> (+<0.01%)	:arrow_up:

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

Files	Coverage Δ
src/Microsoft.Data.Analysis/DataFrameBuffer.cs	84.90% <100.00%> (-0.28%)	:arrow_down:
...Microsoft.Data.Analysis/ReadOnlyDataFrameBuffer.cs	48.71% <100.00%> (ø)
test/Microsoft.Data.Analysis.Tests/BufferTests.cs	99.65% <100.00%> (+<0.01%)	:arrow_up:
...st/Microsoft.Data.Analysis.Tests/DataFrameTests.cs	99.32% <100.00%> (+<0.01%)	:arrow_up:
.../Microsoft.Data.Analysis/VBufferDataFrameColumn.cs	47.18% <73.68%> (+0.20%)	:arrow_up:
...c/Microsoft.Data.Analysis/StringDataFrameColumn.cs	71.42% <60.86%> (-0.22%)	:arrow_down:

... and 26 files with indirect coverage changes