…er (a dirty solution)

# Conflicts:
#	src/System.CommandLine.ApiCompatibility.Tests/ApiCompatibilityApprovalTests.System_CommandLine_api_is_not_changed.approved.txt
#	src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_ParseResult.cs
#	src/System.CommandLine.Tests/DirectiveTests.cs
#	src/System.CommandLine/Builder/CommandLineBuilder.cs
#	src/System.CommandLine/Builder/CommandLineBuilderExtensions.cs
#	src/System.CommandLine/CommandLineConfiguration.cs
#	src/System.CommandLine/Invocation/ParseDirectiveResult.cs
#	src/System.CommandLine/Invocation/SuggestDirectiveResult.cs
#	src/System.CommandLine/ParseResult.cs
#	src/System.CommandLine/Parsing/ParseOperation.cs

…and_options_within_a_command_does_not_matter was calling Directive.GetDefaultName and throwing

introduce public APIs for setting the handler to make it possible to use reference to "this" in Directive handlers

…o pass next handler and invoke it or not

…bility to pass next handler and invoke it or not"

This reverts commit fc987d4.

# Conflicts:
#	src/System.CommandLine.ApiCompatibility.Tests/ApiCompatibilityApprovalTests.System_CommandLine_api_is_not_changed.approved.txt
#	src/System.CommandLine.Tests/DirectiveTests.cs
#	src/System.CommandLine/Parsing/StringExtensions.cs
#	src/System.CommandLine/Parsing/SymbolResultExtensions.cs