Fix composite glyph transform parsing.

[JimBobSquarePants]

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Description

Fixes #334

The wrong property was being set on the transformation matrix when loading the composite glyph.

I used ttfdump to parse the font to determine the correct transform after ensuring there was no shaping taking place and realized then something was amiss.

Glyph    612.
	 numberOfContours:	 -1  (Composite)
	 xMin:			 31
	 yMin:			 -279
	 xMax:			 295
	 yMax:			 768

	 0: Flags:	 0x22
	    Glyf Index:	 748
	    X BOffset:	 31
	    Y BOffset:	 0
	    Others:	                                                   

	 1: Flags:	 0x10b
	    Glyf Index:	 613
	    X WOffset:	 306
	    Y WOffset:	 489
	    X,Y Scale:	 -1.000000
	    Others:	                                                   


	 Length of Instructions:  6

Here's the rendered output following the fix.

[codecov]

Codecov Report

Merging #339 (1696aff) into main (960f46c) will not change coverage.
The diff coverage is 100%.

❗ Current head 1696aff differs from pull request most recent head 956f8c4. Consider uploading reports for the commit 956f8c4 to get more accurate results

@@          Coverage Diff          @@
##            main    #339   +/-   ##
=====================================
  Coverage     83%     83%           
=====================================
  Files        227     227           
  Lines      12859   12859           
  Branches    1839    1838    -1     
=====================================
  Hits       10772   10772           
  Misses      1652    1652           
  Partials     435     435           

Flag	Coverage Δ
unittests	83% <100%> (ø)

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Impacted Files	Coverage Δ
...bors.Fonts/Tables/AdvancedTypographic/GSubTable.cs	92% <100%> (ø)
...nts/Tables/TrueType/Glyphs/CompositeGlyphLoader.cs	100% <100%> (ø)

... and 2 files with indirect coverage changes

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