Add `--trust` cmdline flag to `brew tap` command

### Verification - [x] This issue's title and/or description do not reference a single formula e.g. `brew install wget`. If they do, open an issue at https://github.com/Homebrew/homebrew-core/issues/new/choose instead. ### Provide a detailed description of the proposed feature Starting with Homebrew `5.1.15` it is now necessary to explicitly trust the third-party Tap (unless `HOMEBREW_NO_REQUIRE_TAP_TRUST=1` is set) which requires users to run to consecutive command: `brew tap …` and then `brew trust …`. It would greatly improve user experience if the `brew tap` command provided a `--trust` flag to implicitly do `brew trust …`. Many thanks. ### What is the motivation for the feature? Improve user experience by squeezing two standalone commands to one by means of a feature command-line flag. ### How will the feature be relevant to at least 90% of Homebrew users? Run one single command to tap and trust instead of running two standalone commands. ### What alternatives to the feature have been considered? None. Need to run `brew tap …` and then not forget to run `brew trust …`.