Adds Memory Buffer APIs

[SkyeHoefling]

Fixes: #9

Description

Adds new Memory Buffer APIs, unit tests and benchmarks

IImage - New APIs

byte[] ToArray(int quality = 90);
ReadOnlySpan<byte> ToSpan(int quality = 90);
Stream ToStream(int quality = 90);

Merge Checklist

• Added unit or integration tests (if not explain)
• Benchmarks are equivalent or faster
• Upload new Benchmark results

[github-actions]

Benchmark Comparison

Benchmarking comparison between this Pull Request and the comitted values at benchmarks/results

thumbnail

 summary:
better: 1, geomean: 1.148
total diff: 1

No Slower results for the provided threshold = 10% and noise filter = 0.3ns.

| Faster                                                    | base/diff | Base Median (ns) | Diff Median (ns) | Modality|
| --------------------------------------------------------- | ---------:| ----------------:| ----------------:| -------- |
| FileOnQ.Imaging.Heif.Benchmarks.Thumbnail.Thumbnail_Write |      1.15 |      60288300.00 |      52499750.00 | several?|

No file given
 

primary

 No differences found between the benchmark results with threshold 10%.
 

Benchmark Results

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BenchmarkDotNet=v0.13.0, OS=Windows 10.0.17763.2114 (1809/October2018Update/Redstone5)
Intel Xeon CPU E5-2673 v4 2.30GHz, 1 CPU, 2 logical and 2 physical cores
.NET SDK=5.0.400
 [Host]     : .NET 5.0.9 (5.0.921.35908), X64 RyuJIT
 Job-FJVQTT : .NET 5.0.9 (5.0.921.35908), X64 RyuJIT

Runtime=.NET 5.0  InvocationCount=1  LaunchCount=1  
UnrollFactor=1  

Method	Mean	Error	StdDev	Median	Gen 0	Gen 1	Gen 2	Allocated	Allocated native memory	Native memory leak
Thumbnail_Write	52.41 ms	1.036 ms	2.746 ms	52.50 ms	-	-	-	288 B	5,125,137 B	-
Thumbnail_ToArray	48.68 ms	1.194 ms	3.503 ms	47.95 ms	-	-	-	66,408 B	5,124,581 B	-
Thumbnail_ToSpan	50.10 ms	1.206 ms	3.555 ms	49.83 ms	-	-	-	120 B	5,124,581 B	-
Thumbnail_ToStream	48.84 ms	1.220 ms	3.577 ms	47.63 ms	-	-	-	66,472 B	5,124,581 B	-

primary

BenchmarkDotNet=v0.13.0, OS=Windows 10.0.17763.2114 (1809/October2018Update/Redstone5)
Intel Xeon CPU E5-2673 v4 2.30GHz, 1 CPU, 2 logical and 2 physical cores
.NET SDK=5.0.400
 [Host]     : .NET 5.0.9 (5.0.921.35908), X64 RyuJIT
 Job-UAQZJA : .NET 5.0.9 (5.0.921.35908), X64 RyuJIT

Runtime=.NET 5.0  InvocationCount=1  LaunchCount=1  
UnrollFactor=1  

Method	Mean	Error	StdDev	Gen 0	Gen 1	Gen 2	Allocated	Allocated native memory	Native memory leak
PrimaryImage_Write	2.736 s	0.0409 s	0.0341 s	-	-	-	256 B	222,029,948 B	-
PrimaryImage_ToArray	2.896 s	0.0486 s	0.0596 s	-	-	-	1,943,008 B	222,029,376 B	-
PrimaryImage_ToSpan	2.775 s	0.0372 s	0.0310 s	-	-	-	88 B	222,029,424 B	-
PrimaryImage_ToStream	2.738 s	0.0416 s	0.0389 s	-	-	-	1,943,072 B	222,029,552 B	-

[SkyeHoefling]

This PR requires new benchmark results to be uploaded prior to merging. I added a new checklist item to the PR description

[SkyeHoefling]

I just looked through the code changes and it appears there is issues with tabs in several areas of the code. There are extra tabs or not enough tabs.

I am going to do another pass and push changes

[SkyeHoefling]

@mitchelsellers I think this PR is good, can you take a look and see if I missed any typos or anything. If you think it is good to go please merge it.

I did not add XML docs to this PR as we are going to do all XML docs in #22 for the 1.0.0 release