DH-10111 Fix missing horizontal scroll bar for single column tables

[mattrunyon]

Fixes #446 and related to DH-10111 test failure

This adds a horizontal scroll bar for any single column table which does not fit in the panel fully

Example Python to test with

from deephaven import new_table
from deephaven.column import string_col
import random
import string

letters = string.printable
strings = [''.join(random.choice(letters) for i in range(random.randint(0, 1000))) for j in range(0, 100)]
table1 = new_table([string_col("Random", strings)])

Also tested with changing IrisGridTheme.rowHeaderWidth to be non-zero

[codecov]

Codecov Report

Merging #543 (0a2e183) into main (b24ade4) will decrease coverage by 0.01%.
The diff coverage is 39.81%.

@@            Coverage Diff             @@
##             main     #543      +/-   ##
==========================================
- Coverage   36.38%   36.36%   -0.02%     
==========================================
  Files         390      390              
  Lines       28511    28562      +51     
  Branches     6731     6764      +33     
==========================================
+ Hits        10374    10387      +13     
- Misses      17791    17829      +38     
  Partials      346      346              

Flag	Coverage Δ
unit	36.36% <39.81%> (-0.02%)	⬇️

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

Impacted Files	Coverage Δ
packages/grid/src/Grid.tsx	64.50% <0.00%> (-2.07%)	⬇️
...se-handlers/GridHorizontalScrollBarMouseHandler.ts	34.66% <40.00%> (-2.48%)	⬇️
...ouse-handlers/GridVerticalScrollBarMouseHandler.ts	34.66% <40.00%> (-2.48%)	⬇️
packages/grid/src/GridMetricCalculator.ts	75.39% <87.09%> (+0.03%)	⬆️

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[mofojed]

Shift+Wheel (which should scroll horizontally) isn't working. I think need to update Grid.tsx handleWheel function

[mattrunyon]

Updated so vertical scroll uses the same logic as horizontal

Tested by setting a big rowHeight in IrisGridTheme.module.scss. Also fixed/tested horizontal scroll with scrollSnapToColumn: true in IrisGridTheme.ts