Ability to run post-install anonymous scripts on unlocked packages #1338

Is your feature request related to a problem? Please describe.
Currently, we are only able to run post-install anonymous scripts for 2GP managed packages.

What are you trying to do
Execute anonymous scripts after the install of an unlocked package, so we can automate some action like record creation after the package is installed. We want the setup and record creation for an unlocked package to be fully automated from an SFDX command so that we can avoid missing manual steps after an unlocked package installation.

Describe the solution you'd like
Ability to specify one or multiple anonymous scripts in the sfdx-project.json file of an SFDX project that is an unlocked package, and the script(s) will execute after the unlocked package is installed into a Salesforce org.

Describe alternatives you've considered
SFDX plugin, internal wrapper CLI solution, manually executing scripts after package installation

Additional context
Add any other context or screenshots about the feature request here.