Add padding support to Syntax

[darrenburns]

Type of changes

• Bug fix
• New feature
• Documentation / docstrings
• Tests
• Other

Checklist

• I've run the latest black with default args on new code.
• I've updated CHANGELOG.md and CONTRIBUTORS.md where appropriate.
• I've added tests for new code.
• I accept that @willmcgugan may be pedantic in the code review.

Description

Add padding support to Syntax.

Closes #2240

[codecov-commenter]

Codecov Report

Merging #2247 (b18d59f) into master (14d47c9) will decrease coverage by 0.08%.
The diff coverage is 96.46%.

@@            Coverage Diff             @@
##           master    #2247      +/-   ##
==========================================
- Coverage   98.88%   98.80%   -0.09%     
==========================================
  Files          73       73              
  Lines        7629     7668      +39     
==========================================
+ Hits         7544     7576      +32     
- Misses         85       92       +7     

Flag	Coverage Δ
unittests	98.80% <96.46%> (-0.09%)	⬇️

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

Impacted Files	Coverage Δ
rich/_export_format.py	100.00% <ø> (ø)
rich/console.py	98.28% <95.87%> (-0.50%)	⬇️
rich/syntax.py	99.30% <100.00%> (+0.02%)	⬆️
rich/terminal_theme.py	100.00% <100.00%> (ø)
rich/traceback.py	98.68% <0.00%> (-0.88%)	⬇️

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[willmcgugan]

Great. Would you mind updating CHANGELOG before merging.