BitmapByteQRCode performance optimization

[codebude]

Summary

I tried to optimize the performance of BitmapByteQRCode by removing loops and pre-calculating data where possible. Also fixed object size/capacity to keep memory footprint low.

Performance details

Before this PR

Method	Mean	Error	StdDev	Gen0	Gen1	Gen2	Allocated
RenderBitmapByteQRCodeSmall	2.369 ms	0.0457 ms	0.0489 ms	496.0938	210.9375	210.9375	7.22 MB
RenderBitmapByteQRCodeMedium	7.903 ms	0.1557 ms	0.1456 ms	1734.3750	750.0000	750.0000	21.26 MB
RenderBitmapByteQRCodeBig	89.976 ms	1.0133 ms	0.8983 ms	18000.0000	2166.6667	2166.6667	265.99 MB
RenderBitmapByteQRCodeHuge	2,090.730 ms	33.4541 ms	31.2930 ms	407000.0000	8000.0000	8000.0000	6775.64 MB

After/with changes from this PR

Method	Mean	Error	StdDev	Gen0	Gen1	Gen2	Allocated
RenderBitmapByteQRCodeSmall	115.1 us	2.29 us	4.83 us	153.8086	153.8086	153.8086	495.75 KB
RenderBitmapByteQRCodeMedium	163.1 us	3.16 us	4.11 us	299.0723	298.8281	298.8281	1412.45 KB
RenderBitmapByteQRCodeBig	3,156.9 us	62.66 us	87.84 us	988.2813	988.2813	988.2813	18372.12 KB
RenderBitmapByteQRCodeHuge	74,284.9 us	1,432.76 us	1,961.18 us	1000.0000	1000.0000	1000.0000	458983.6 KB

After implementing changes suggested by @Shane32 via PR review

Method	Mean	Error	StdDev	Gen0	Gen1	Gen2	Allocated
RenderBitmapByteQRCodeSmall	73.79 us	0.901 us	0.799 us	76.9043	76.9043	76.9043	247.3 KB
RenderBitmapByteQRCodeMedium	208.30 us	3.268 us	2.897 us	199.9512	199.9512	199.9512	704.85 KB
RenderBitmapByteQRCodeBig	1,162.20 us	22.314 us	25.697 us	500.0000	500.0000	500.0000	9182.63 KB
RenderBitmapByteQRCodeHuge	57,819.92 us	1,858.610 us	5,450.982 us	833.3333	833.3333	833.3333	229479.24 KB

Test plan

To ensure that the optimizations work out and break anything I added test cases and benchmarks to the project.

[codebude]

@Shane32 May I ask you for a review? (Please be critical with the benchmark project. I tried to exclude the QRCode data generation, as it is ramp-up stuff, from the benchmarks, but I'm not sure, if I did it right.)

[Shane32]

Looks great! Benchmarks look great! I've just jotted down some notes for additional improvements that could be made, whether that be within this PR or another one.

[codebude]

Looks great! Benchmarks look great! I've just jotted down some notes for additional improvements that could be made, whether that be within this PR or another one.

Hi Shane, thanks for your review. I implemented and tested all of your suggestions. Thanks for the great input! :-)
The results have improved once again. (I have inserted the new benchmarks in the first post above).