Add Expand-DarkArchive and some other dependency features

[r15ch13]

• Add Expand-DarkArchive helper function
• Allow dark.exe from wixtoolset and 7zip-zstd as valid helpers
• Add warnings to 'scoop checkup' for missing unpackers
• Auto detect dependencies from pre_install/post_install and installer.script by simply searching for the function names.

Should be merge into develop before merging develop into master.
This will allow us to remove the dark dependency from some manifests.
Expand-7zipArchive is widely used without the manifest actually depending on it.
The installation will fail with the following message when Get-HelperPath returns nothing.

The expression after '&' in a pipeline element produced an object that was not valid. It must result in a command name, a script block, or a CommandInfo object.

#3417

[niheaven]

dark needn't a seperated Expand- function since it is only used when we want to unpack WIX type installer. After using dark, we need extract_msi...

[r15ch13]

@niheaven using this function will make manifest scripts cleaner and it's easier to use.