Codesign MetaCall distributable

[FirePing32]

MetaCall installed via .pkg does not require code signing, but the MetaCall launcher extracted from the .tgz distributable fails due to an invalid code signature. All the MetaCall core files need to be manually verified to remove Gatekeeper warnings. The distributable must be notarized before distribution in the CI.

[viferga]

I found an alternative, we can use fallback to brew and build NodeJS and MetaCall from scratch, now I have replaced the Homebrew recipe in order to use prebuilt libnode from metacall/libnode repo, but we can provide an alternative method to build (through an environment variable or something like that), and use this as fallback when the computer has disabled the installation of unsigned software. Another option would be to just correct the problems with Homebrew recipe and PR it into Homebrew repo.

For reference:

• This is the current method for Homebrew installing prebuilt libnode: https://github.com/metacall/homebrew/blob/88271cf1605b56beeb2847a8731fa611098641b8/metacall.rb#L15
• This is the previous method for Homebrew that used to build libnode: https://github.com/metacall/homebrew/blob/0b178d023b62d4551d65f936ec67e8c3e49082f3/metacall.rb
• Here is the requirements for being able to publish into Homebrew (this will solve signing and we can do the fallback in metacall/install without need of building libnode): Solve issues listed in PR of homebrew-core and PR it again homebrew#16
• Here's the TODO for implementing the fallback in metacall/install: https://github.com/metacall/install/blob/dc241a113a122c8c76933d7a1a3aae6a76425d50/install.sh#L854