Optimize parsing of color strings into KnownColor enum, remove allocations

[h3xds1nz]

Description

Removes conversion of the color string into uppercase and its subsequent compare with StringComparison.OrdinalIgnoreCase.
The replacement was done by a simple regex.

Method	colorString	Mean [ns]	Error [ns]	StdDev [ns]	Gen0	Code Size [B]	Allocated [B]
Original	SlateGray	18.853 ns	0.3373 ns	0.3155 ns	0.0024	6,066 B	40 B
PR__EDIT	SlateGray	2.155 ns	0.0072 ns	0.0060 ns	-	6,695 B	-

Customer Impact

Increased performance on serialization, zero allocations.

Regression

No.

Testing

Local build/CI/assert test.

foreach (string color in Enum.GetNames<KnownColor>())
{
    KnownColor constantColor = Enum.Parse<KnownColor>(color);

    KnownColor lowerCase = ColorStringToKnownColorNEW(color.ToLowerInvariant());
    KnownColor upperCase = ColorStringToKnownColorNEW(color.ToUpperInvariant());
    KnownColor normalColor = ColorStringToKnownColorNEW(color);

    Assert.AreEqual<KnownColor>(constantColor, lowerCase);
    Assert.AreEqual<KnownColor>(constantColor, upperCase);
    Assert.AreEqual<KnownColor>(constantColor, normalColor);
}

Risk

Low.

Microsoft Reviewers: Open in CodeFlow

[siagupta0202]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[siagupta0202]

LGTM

[siagupta0202]

@h3xds1nz Thank you for your contributions!

[h3xds1nz]

@siagupta0202 Thank you :)