completion: misc updates

[casperdcl]

Follow-up to #3921

• update shtab dependency (>=1.0.0, or likely >=1.1.0) completion: misc fixes #4076
• hide/skip certain subcommands (e.g. daemon) completion: misc fixes #4076
  • shtab>=1.0.0 completion: autogenerate #3921 (comment)
• hide/skip certain arguments & options completion: misc fixes #4076
  • shtab>=1.0.0 <- hide SUPPRESSed options shtab#3
• introduce consistency calling DVC-files targets, other files paths, and directories dirs
• introduce consistency around leading vs trailing whitespace when linebreaking strings