Multicall has a performance impact on start-up

[fishface60]

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Clap Version

3.0.0-beta.4

Describe your use case

AppSettings::Multicall causes it to check the executable name against all applet names first and then later against the program name.

If the base program name is not the same as any applets we can match against it first, which may be faster if we expect to access it via that name more often than as an applet link.

Describe the solution you'd like

We can know in advance that the base program name is not the same as an applet by checking the name of an added subcommand against the base program name and set an internal flag to match against base program name first.

Alternatives, if applicable

We could WONTFIX this as we don't expect program start-up to be hot code.

Additional Context

No response