fix: repair invalid fish shell completion code

[manuraj17]

Fixes related to #1934 & #1908

Earlier changes introduced in #1912 broke the fish shell completions. The changes were for both zsh and fish. Though, here we are making changes only for fixing fish.

There is room for improvement but the fix right now is focused to make the broken stuff work.

Below commands are removed

• global
• local
• update

[Stratus3D]

I don't see a suggestion for asdf plugin:

~> asdf 
current  (Display version set or being used for package)  set                                       (Set version for a plugin)
info        (Print OS, Shell and ASDF debug information)  shimversions  (List the plugins and versions that provide a command)
install        (Install a specific version of a package)  uninstall                   (Remove a specific version of a package)
latest         (Show latest stable version of a package)  where                (Display install path for an installed version)
list              (List installed versions of a package)  which                        (Display executable path for a command)
reshim         (Recreate shims for version of a package) 

Plugin should be presented here as it is an option.

[manuraj17]

@Stratus3D Added plugin option

I feel there could be more refinements for ex: currently asdf plugin list <tab> gives an all out list and then all. I can check on them, but since the current release has this broken maybe I can work on those incrementally since this works at the moment.

[Stratus3D]

Thanks @manuraj17 !