Implement `brew trust`

[buresdv]

Starting in Homebrew 6.0.0 or 5.2.0, whichever comes first, they will start enforcing a type of Homebrew Gatekeeper. Support for this Gatekeeper should be added

Command overview

• brew trust shows the current status of trusted taps and packages, in the following format:

brew trust
All official taps and commands are trusted.
No trusted taps, formulae, casks or commands.

• brew untrust shows a list of taps and packages that are not trusted, in the following format:

brew untrust
Untrusted taps:
  derailed/k9s
  marsanne/cask
  playcover/playcover
Untrusted formulae:
  derailed/k9s/k9s
  playcover/playcover/inject
  playcover/playcover/playmap
Untrusted casks:
  marsanne/cask/cork
  marsanne/cask/virustotal
  playcover/playcover/ipa-source-generator
  playcover/playcover/playcover-community
  playcover/playcover/playcover-nightly
  playcover/playcover/sideloadly

• Warning in console:

Warning: The following taps are not trusted:
  derailed/k9s
  marsanne/cask
  playcover/playcover

Homebrew will ignore formulae, casks and commands from these taps when `HOMEBREW_REQUIRE_TAP_TRUST` is set.
This will become the default in Homebrew 6.0.0 or 5.2.0, whichever comes first.
Enable trust checks now with:
  export HOMEBREW_REQUIRE_TAP_TRUST=1
Trust specific formulae, casks or commands with:
  brew trust --formula <user>/<tap>/<formula>
  brew trust --cask <user>/<tap>/<cask>
  brew trust --command <user>/<tap>/<command>

You can trust all formulae, casks and commands from these taps with:
  brew trust derailed/k9s marsanne/cask playcover/playcover
Prefer trusting only the specific formulae, casks or commands you need.
Untap them with:
  brew untap derailed/k9s marsanne/cask playcover/playcover
To keep allowing them by default during the transition:
  export HOMEBREW_NO_REQUIRE_TAP_TRUST=1
This is not recommended and will be removed in a later release.

Homebrew overview

There is a JSON file that describes which taps / packages are trusted, make use of these tickets:

• Avoid creating ~/.homebrew/trust.json or provide a way to do so Homebrew/brew#22504
• Document XDG trust config Homebrew/brew#22506

Structure of JSON file

{
  "trustedformulae": [
    "marsanne/cask/cork"
  ],
  "trustedcasks": [
    "marsanne/cask/cork"
  ],
  "trustedtaps": [
    "marsanne/cask"
  ]
}