fix(sqllab): Replace margin style by gap on query results

[justinpark]

SUMMARY

The horizontal scrollbar in query results has been cut off due to the top margin. There's a bunch of redundant margin for adjustment which makes this kind of overflow hidden regression.
This commit replaces this margins by the upper wrapper's gap as well as removing the antd style overrides.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

After:

Before:

TESTING INSTRUCTIONS

Go to sqllab and run a query that contains more than 20.

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[codecov]

Codecov Report

Merging #24772 (27637dc) into master (abb8e28) will decrease coverage by 8.83%.
The diff coverage is 82.60%.

❗ Current head 27637dc differs from pull request most recent head e4993fd. Consider uploading reports for the commit e4993fd to get more accurate results

@@            Coverage Diff             @@
##           master   #24772      +/-   ##
==========================================
- Coverage   67.23%   58.41%   -8.83%     
==========================================
  Files        1902     1902              
  Lines       73939    73997      +58     
  Branches     8176     8195      +19     
==========================================
- Hits        49713    43224    -6489     
- Misses      22113    28654    +6541     
- Partials     2113     2119       +6     

Flag	Coverage Δ
javascript	55.79% <83.51%> (+0.04%)	⬆️
mysql	?
postgres	?
sqlite	?

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Files Changed	Coverage Δ
...frontend/src/SqlLab/components/SouthPane/index.tsx	79.54% <ø> (ø)
...-frontend/src/components/FilterableTable/index.tsx	75.59% <ø> (ø)
superset-frontend/src/components/Select/utils.tsx	82.25% <ø> (-1.62%)	⬇️
superset/views/api.py	60.93% <0.00%> (-7.82%)	⬇️
superset-frontend/src/components/Select/Select.tsx	85.78% <77.04%> (-4.86%)	⬇️
...set-frontend/src/components/Select/AsyncSelect.tsx	89.32% <96.42%> (+0.85%)	⬆️
...frontend/src/SqlLab/components/ResultSet/index.tsx	63.29% <100.00%> (+0.23%)	⬆️

... and 350 files with indirect coverage changes

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[michael-s-molina]

This is adding space vertically and horizontally while previously we had only vertical spacing with padding: ${({ theme }) => 2 * theme.gridUnit}px 0;. Is this intended or should we use row-gap?

[justinpark]

updated

[michael-s-molina]

LGTM