FINERACT-1932: modularization fineract-shares

[alberto-art3ch]

Description

Extracts the Shares domain layer (share account & share product entities, repositories, repository wrappers, status enums and related exceptions) out of fineract-provider into a new standalone Gradle module fineract-shares, continuing the modularization effort alongside fineract-savings and fineract-loan.

FINERACT-1932

• New fineract-shares module (build.gradle, dependencies.gradle) registered in settings.gradle, root build.gradle and wired as a dependency of fineract-provider.
• Moved the shareaccounts/shareproducts domain classes (via git mv to preserve history); packages are unchanged so existing imports keep working.
• Added a fineract.module.shares.enabled toggle (FineractProperties + application.properties / application-test.properties) and a SharesModuleIsEnabledCondition guarding the shares command handlers and API resources.

Checklist

Please make sure these boxes are checked before submitting your pull request - thanks!

• Write the commit message as per our guidelines
• Acknowledge that we will not review PRs that are not passing the build ("green") - it is your responsibility to get a proposed PR to pass the build, not primarily the project's maintainers.
• Create/update unit or integration tests for verifying the changes made.
• Follow our coding conventions.
• Add required Swagger annotation and update API documentation at fineract-provider/src/main/resources/static/legacy-docs/apiLive.htm with details of any API changes
• This PR must not be a "code dump". Large changes can be made in a branch, with assistance. Ask for help on the developer mailing list.

Your assigned reviewer(s) will follow our guidelines for code reviews.