pixi run should invoke the shell's autocompletion

[pavelzw]

Problem description

It would be nice to be able to invoke the shell's autocompletion when using pixi run.

pixi run b<tab>
# becomes
pixi run build

# if no matching pixi task is found, the shell's autocompletion could be called
pixi run git ch<tab>
# becomes
pixi run git checkout

[baszalmstra]

Slightly related to #136

[ruben-arts]

This is now in v0.7.0 for bash and zsh.
We still need support for the other shell's.

If anyone wants to give it a go, checkout the replace functions in this file

[pavelzw]

This is now in v0.7.0 for bash and zsh.

@ruben-arts is it? Or did you only mean the first part?

With the latest pixi version on zsh, I get

❯ pixi run git ch<TAB>
--color              -- Whether the log needs to be colored
--environment    -e  --
--frozen             -- Don't check or update the lockfile, continue with prev
--help           -h  -- Print help
--locked             -- Check if lockfile is up to date, aborts when lockfile
--manifest-path      -- The path to 'pixi.toml'
--quiet          -q  -- Decrease logging verbosity
--verbose        -v  -- Increase logging verbosity
                          postinstall               test

instead of

❯ pixi run git ch<TAB>
check-attr       -- display gitattributes information
check-ignore     -- debug gitignore/exclude files
check-mailmap    -- show canonical names and email addresses of contacts
check-ref-format -- ensure that a reference name is well formed
checkout         -- checkout branch or paths to working tree
checkout-index   -- copy files from index to working directory
cherry           -- find commits not merged upstream
cherry-pick      -- apply changes introduced by some existing commit

[ruben-arts]

The task name autocompletion is in, I don't see a way we'll ever be able to comfortably implement the activated environment autocompletion passthrough.

[ruben-arts]

We're not going to be able to do this anytime soon because of the activation and no dynamic completion in clap. Closing this for now.