feat: unified autocomplete entrypoint

[molisani]

Describe your changes
The core exposes a function proposeCompletions that is responsible for generating a set of completions for the given app + inputs. However, there needs to be some "glue" to adapt that function for each shell. At the moment, the only shell that's supported is bash (but that is going to change). Currently the "glue" is written into the new application template, which makes it virtually impossible to change and it is only implementing the bash "glue".

This PR adds a new handleCompletionsForShell function to @stricli/auto-complete that accepts the same args as proposeCompletions AND the kind of shell. It then handles the "glue" for that specific shell kind and resolves async. This will allow for changes to this logic to be handled "internally" to these packages, and doesn't require any application-owner changes to support a new shell (once it is supported by @stricli/auto-complete). To this end, there are new install-all and uninstall-all commands that will attempt to install/uninstall the autocomplete functionality for every supported shell all at once.

Testing performed
Unit tests exercise the new behavior of @stricli/auto-complete for bash that handles editing the .bashrc and generating the completions (making sure the inputs and outputs are correct). There are also changes to the @stricli/create-app baselines to account for the changes in autocomplete handling.

These changes were also confirmed manually by generating a new application with @stricli/create-app and verifying the behavior in a bash shell.