ci: add collect-modules action

[babinskiy]

This pull request includes several changes to automate the collection of Terraform modules and update configuration files. The most important changes include adding a custom GitHub action to find Terraform modules, modifying the CI workflow to use this action, and updating configuration files.

Automation of Terraform module collection:

• Added a custom GitHub action in .github/actions/collect-modules/action.yaml to find Terraform modules in the repository and output their paths.
• Updated the CI workflow in .github/workflows/ci.yml to include a new job collect-modules that uses the custom action to find Terraform modules and outputs their paths.
• Modified the terraform-docs job in .github/workflows/ci.yml to depend on the collect-modules job and use the collected module paths.

Configuration file updates:

• Added default and profile-based configuration settings in asset-account/terraform/config.ini.
• Added default and profile-based credentials in asset-account/terraform/credentials.ini.
• Created a .module.toml file in asset-account/terraform/stack-set to define the module type and metadata.