[API proposal] "Implicit" property for ArgumentResult just like OptionResult has

[elgonzo]

OptionResulthas an Implicit property:

command-line-api/src/System.CommandLine/Parsing/OptionResult.cs

Lines 32 to 36 in 7bb08a6

	/// <summary>
	/// Indicates whether the result was created implicitly and not due to the option being specified on the command line.
	/// </summary>
	/// <remarks>Implicit results commonly result from options having a default value.</remarks>
	public bool Implicit => IdentifierToken is null || IdentifierToken.Implicit;

Since arguments can also have a DefaultValueFactory like options, it would make sense for ArgumentResult to also have an Implicit property like OptionResult.

Tangent: I don't know about the naming conventions and whether the property name is already locked in, but for a boolean read-only property like that, wouldn't a name like IsImplicit be more suitable?

[jonsequitur]

Tangent: I don't know about the naming conventions and whether the property name is already locked in, but for a boolean read-only property like that, wouldn't a name like IsImplicit be more suitable?

Implicit was recommended during API review over IsImplicit. This is aligned to the .NET naming guidelines though it's more of a suggestion than a rule. https://learn.microsoft.com/en-us/dotnet/standard/design-guidelines/names-of-type-members#names-of-properties