feat: support enum naming strategies for DescriptionAttribute and Enu…

[latonz]

Adds support for the System.ComponentModel.DescriptionAttribute and System.Runtime.Serialization.EnumMemberAttribute as enum naming strategies.
Fixes #1079

[josetr]

@latonz Are there any plans to allow empty names?

Newtonsoft did support [EnumMember(Value = "")]].

Use case: https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#codeActionKind

[latonz]

@josetr IMO this should already work:

mapperly/test/Riok.Mapperly.Tests/Mapping/EnumNamingStrategyTest.cs

Lines 241 to 281 in 5333523

	[Fact]
	public void EnumToStringWithSerializationEnumMemberAttributeNamingStrategy()
	{
	var source = TestSourceBuilder.MapperWithBodyAndTypes(
	"[MapEnum(EnumMappingStrategy.ByName, NamingStrategy = EnumNamingStrategy.SerializationEnumMemberAttribute)] public partial string ToStr(E source);",
	"""
	public enum E
	{
	[System.Runtime.Serialization.EnumMember(Value = "A1")] A,
	[System.Runtime.Serialization.EnumMember(Value = "")] B,
	[System.Runtime.Serialization.EnumMember(Value = null)] C,
	[System.Runtime.Serialization.EnumMember)] D,
	E,
	}
	"""
	);
	TestHelper
	.GenerateMapper(source, TestHelperOptions.AllowInfoDiagnostics)
	.Should()
	.HaveSingleMethodBody(
	"""
	return source switch
	{
	global::E.A => "A1",
	global::E.B => "",
	global::E.C => "C",
	global::E.D => "D",
	global::E.E => "E",
	_ => source.ToString(),
	};
	"""
	)
	.HaveDiagnostics(
	DiagnosticDescriptors.EnumNamingAttributeMissing,
	"The EnumMemberAttribute to build the name of the enum member C (2) is missing",
	"The EnumMemberAttribute to build the name of the enum member D (3) is missing",
	"The EnumMemberAttribute to build the name of the enum member E (4) is missing"
	)
	.HaveAssertedAllDiagnostics();
	}

Can you elaborate on what exactly doesn't work as expected?