Include name of argument when an argument is missing

[samblackburn]

Closes #1074

Reimplementation of #1993 which went quiet in 2023 and now has a ton of merge conflicts.

AI disclaimer: I made this PR while playing with Claude Code.

While the Latin languages look correct to me, I haven't verified the other translations.

[samblackburn]

@dotnet-policy-service agree company="Redgate Software Ltd"

[jonsequitur]

This test is probably not sufficient to test this change. It would be helpful to see additional testing where a command has multiple Argument<T> objects.

This kind of test isn't really about localization. Maybe add a test alongside this one for this case:

command-line-api/src/System.CommandLine.Tests/ParserTests.cs

Lines 1504 to 1521 in 12473cd

	[Fact]
	public void When_command_arguments_are_fewer_than_minimum_arity_then_an_error_is_returned()
	{
	var command = new Command("the-command")
	{
	new Argument<string[]>("arg")
	{
	Arity = new ArgumentArity(2, 3)
	}
	};
	var result = command.Parse("1");
	result.Errors
	.Select(e => e.Message)
	.Should()
	.Contain(LocalizationResources.RequiredArgumentMissing(result.GetResult(command.Arguments[0])));
	}

[samblackburn]

Thanks for the review. I've added a test for multiple missing args - is that what you were looking for?