fix!: Require explicit help/version disabling

[epage]

Before we introduced actions, it required specific setups to engage with
claps version and help printing. With actions making that more
explicit, we don't get as much benefit from our multiple, obscure, ways
of users customizing help

Before

• Modify existing help or version with mut_arg which would
  automatically be pushed down the command tree like global(true)
• Create an new help or version and have it treated as if it was the
  built-in on (I think)
• Use the same flags as built-in and have the built-in flags
  automatically disabled
• Users could explicitly disable the built-in functionality and do what
  they want

Now

• mut_arg no longer works as we define help and version flags at the
  end
• If someone defines a flag that overlaps with the built-ins by id,
  long, or short, a debug assert will tell them to explicitly disable
  the built-in
• Any customization has to be done by a user providing their own. To
  propagate through the command tree, they need to set global(true).

Benefits

• Hopefully, this makes it less confusing on how to override help
  behavior. Someone creates an arg and we then tell them how to disable
  the built-in
• This greatly simplifies the arg handling by pushing more
  responsibility onto the developer in what are hopefully just corner
  cases
• This removes about 1Kb from .text

Fixes #3405
Fixes #4033