fix: Clean up all previous finch version installation registries in postinstall and uninstall

[KevinLiAWS]

Issue #, if available:
#687
Old finch installation registry remains if uninstall script not explicitly called, the mac will treat a new installation with upgrade info message.

Description of changes:
Added a full clean up step in the postinstall script to remove all old registries except the current installed version. Also make the uninstall script not only remove the current but also remove all historical registry record.

Testing done:
Tested with cloud build: https://github.com/runfinch/finch/actions/runs/6791189430
Also validated locally with pkg installation:

// Before install the fixed pkg, it print all finch registries
% pkgutil --pkgs | grep '^org\.Finch'
org.Finch.v0.8.0
org.Finch.pkg-tool
org.Finch.v0.7.0
org.Finch.v0.6.2
org.Finch.main
org.Finch.0.6.0
org.Finch.0.4.1
org.Finch.0.4.0

// After install the fixed pkg, it only has the current registry
% pkgutil --pkgs | grep '^org\.Finch'
org.Finch.fix-unregistry

// After execute uninstall, all the registries are removed
% pkgutil --pkgs | grep '^org\.Finch'
% // empty

• I've reviewed the guidance in CONTRIBUTING.md

License Acceptance

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[pendo324]

This will work as long as we only allow one version of Finch to be installed per machine (which we do now, so no concerns). Just something to think about if we ever allow changing the install location, or per-user installs.

[KevinLiAWS]

This will work as long as we only allow one version of Finch to be installed per machine (which we do now, so no concerns). Just something to think about if we ever allow changing the install location, or per-user installs.

For this concern:

1. pkg forget always need admin permission
2. mac os standard pkg installation is system level, if we support user level installation, pkgutil will be not in the scope, it only maintains system level registry. In other words, user level installation doesn't need to touch pkg registry or forget. When we support user installation case, we can add addtional check based on some condition, such as the location software is installed.