feat: add hideAliases help option

[mdonnalley]

• Adds hideAliasesFromRoot to HelpOptions. When true, it filters command aliases from the COMMANDS section of the root help
• Adds hiddenAliases property to Command allowing you to create command aliases that won't be visible in the help output

Fixes oclif/oclif#888

[git2gus]

This issue has been linked to a new work item: W-14278511

[ryandagg]

Thank you!

[WillieRuemmele]

QA Notes

---

setup:

build and link this PR into an OCLIF plugin

---

hidden aliases

add public static readonly hiddenAliases=['hidden']; to a command

✅ : ./bin/dev hidden runs the command
✅ : not present in ./bin/dev output
✅ : not present in --help alias section

help options

add

    "helpOptions": {
      "hideAliasesFromRoot": true
    },

to pjson.oclif

✅ : when true, hides aliases from bin output

 ➜  ./bin/dev 
demo plugin for testing
...

COMMANDS
  demo  Summary of a command.
  help  Display help for sf.

✅ : when omitted, or set to false

 ➜  ./bin/dev 
demo plugin for testing

...

COMMANDS
  demo     Summary of a command.
  help     Display help for sf.
  myalias  Summary of a command.