Now that we are loading package autoloads files (as part of the
generated doom-package-autoload-file when running make autoloads), many
:commands properties are redundant. In fact, many def-package! blocks
are redundant.
In some cases, we can do without a config.el file entirely, and can move
into the autoloads file or rely entirely on package autoloads.
Also, many settings have been moved in their module's autoloads files,
which makes them available ASAP; their use no longer depends on module
load order.
This gained me a modest ~10% boost in startup speed.
Now that auth-password-store has been renamed to auth-source-pass and it matches
the same feature included in emacs 26 under the same name we don't need custom
checks and package loading.