Closes #11568
Closes #11570

As reported by https://geoff.greer.fm/lscolors

Fixes #11554

Was linking to an old URL

This fixes an edge case where the user actually sets

  zstyle ':completion:*' list-colors

in their zshrc, but the previous code used a precmd hook, which would
override the user changes. With this change our modifications will be
set in the init script, after the theme loads, so that later changes
can affect our defaults.

Note that this will not be run for users on plugin managers, as these
don't generally run our init script.

Co-authored-by: Sumudu Lansakara <sumudu.lansakara@ppro.com>

Closes #9900

Co-authored-by: Andrew Janke <janke@pobox.com>
Co-authored-by: Marcelo Parada <marcelo.parada@axoninsight.com>
Co-authored-by: Uy Ha <hchanuy@gmail.com>
Co-authored-by: Valentin Uveges <valentin.uveges@gmail.com>

Fixes #11098

Co-authored-by: Marc Cornellà <hello@mcornella.com>

Co-authored-by: Matthew Boston <matthew@matthewboston.com>

Fixes #11503

Fixes #11524

Closes #11497

Closes #11507

Co-authored-by: Carlo Sala <carlosalag@protonmail.com>

Revert fcbfdf42

Closes #8457 
Closes #9973 

Closes #11501

Latest snap installs gcloud at /snap/google-cloud-cli, so add that to
the list of possible locations.