Set correct tap when loading installed casks

[Rylan12]

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Fixes #17416

This PR uses the new cask tabs to set the correct tap when loading an installed cask.

I have added two new CaskLoader methods:

1. load_installed_cask: this method is analogous to Formulary::from_keg. It accepts a token and returns a cask with that token from the tap specified in the install receipt of the cask. Essentially, if slack was installed from test/tap, running load_installed_cask("slack") will return the test/tap/slack cask and not the homebrew/cask/slack cask. Note: if a full name is passed, the tap specified in the name will be used, even if a different tap exists in the install receipt.
2. load_from_installed_caskfile: this method takes an installed caskfile and loads a cask from it, making sure to set the correct tap. If passed a path that isn't an installed caskfile or doesn't exist, it will raise a CaskUnavailableError.

This means that Cask::Caskroom::casks will now return the correct casks when a third-party cask is installed and shares a name with a cask in homebrew/cask. This means that brew list --full-name will work correctly.

Additionally, handling of named arguments when requesting kegs or keg-like-casks (i.e. installed formulae/casks). Now, specifying a full name will raise an error if the installed formula with that short name does not have a matching tap. For example, if test/tap/hello is installed, brew uninstall homebrew/core/hello will not uninstall the formula. brew uninstall hello and brew uninstall test/tap/hello will still work as expected.

[Rylan12]

I accidentally duplicated some of the work in #17821, so this might need to be modified around that PR depending on which route makes more sense

[apainintheneck]

The changes to named args seem like good sanity checks but it's not obvious to me that they accurately handle migrated/renamed packages or prevent name conflicts when trying to load installed packages. I'm still not sure where or how this should be handled. It doesn't need to be handled in this PR though; I'm just thinking out loud.

We currently have named_args [:installed_formula, :installed_cask] throughout the codebase but as far as I can tell that information is only really used for documentation and not acted upon anywhere.

In some places, we load formula from kegs or racks and that sort of works but we don't have a good way of doing the same thing for casks yet since that possibility is so new.

Would it be helpful to have a keg for casks that represents the directory in the cask room where the cask has been installed? This would give us easy access to the installed cask file, install receipt and config settings without having to load a cask at all. Naming might be tricky though (shelf, stand, etc.).

[apainintheneck]

The changes to Homebrew::Cli::NamedArgs look good to me. I looked at the code a bit more and it seems that the #to_*_kegs methods are used in brew list, brew uninstall, brew link and brew unlink. The last three of those could potentially cause hard to debug problems if the wrong formula or cask is used.

[MikeMcQuaid]

Looks great, thanks @Rylan12! Feel free to resolve any comments and self-merge when you're ready.

[Rylan12]

Sorry all, I know there are unanswered questions here and it's been a while. I haven't forgotten and I will return to this in the next two or three days

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[Rylan12]

Sorry for disappearing off the face of the earth for a few weeks...

I've made some changes to address the open comments a little bit

We currently have named_args [:installed_formula, :installed_cask] throughout the codebase but as far as I can tell that information is only really used for documentation and not acted upon anywhere.

Not important to this PR but: these also affect shell completions

[MikeMcQuaid]

Thanks @Rylan12!

[apainintheneck]

Great work here!