stop padding new append vecs to page size

[jeffwashington]

Problem

We no longer 'append' to append vecs. We know the full size when we are ready to write to them. So, it is no longer necessary to pad them to the next full page size. This makes 100% of the data in the file required and the used length equal to the allocated length.

This pr was attempted as #33607 but reverted as #33634.
There were 2 conflicting prs. There was a failing test. That test has now been fixed.

Summary of Changes

Fixes #

[brooksprumo]

lgtm

[codecov]

Codecov Report

Merging #33658 (1d4ab52) into master (fa21a3d) will decrease coverage by 0.1%.
Report is 7 commits behind head on master.
The diff coverage is 100.0%.

@@            Coverage Diff            @@
##           master   #33658     +/-   ##
=========================================
- Coverage    81.8%    81.8%   -0.1%     
=========================================
  Files         806      806             
  Lines      217477   217472      -5     
=========================================
- Hits       178026   178008     -18     
- Misses      39451    39464     +13