traverse: collect context information about args #922

Request

Since traverse already iterates over the arguments and identifies them this should be stored and optionally returned.

Proposed solution

Provide an array of context information:

• value of the arg
• name of flag/subcommand
• desctiption of flag/subcommand
• type (flag type | argument type | command)
• optarg (embed the same if it is an optarg)

Anything else?

gh issue --repo rsteube/carapace list --label enhancement --state open --web

Could be visualized like:

gh # GitHub CLI
issue # Manage issues
  --repo rsteube/carapace # Select another repository using the `[HOST/]OWNER/REPO` format
list #  List issues in a repository
  --label enhancement # Filter by label
  --state open # Filter by state: {open|closed|all}
  --web # List issues in the web browser