[Feature] Support for MANAGE privilege in dbt's +grants configuration (Databricks Unity Catalog)

### Is this your first time submitting a feature request?

- [x] I have read the [expectations for open source contributors](https://docs.getdbt.com/docs/contributing/oss-expectations)
- [x] I have searched the existing issues, and I could not find an existing issue for this feature
- [x] I am requesting a straightforward extension of existing dbt functionality, rather than a Big Idea better suited to a discussion

### Describe the feature

I would like to request support for the MANAGE privilege in dbt's +grants configuration block, specifically for use with Databricks Unity Catalog.

[Unity Catalog now supports the MANAGE privilege](https://docs.databricks.com/aws/en/data-governance/unity-catalog/manage-privileges/) on various object types (e.g., SCHEMA, TABLE, VIEW, FUNCTION, etc.). This privilege allows users to manage permissions, drop/rename objects, and transfer ownership — making it a powerful tool for enterprise-level governance.

Currently, dbt supports a limited set of privileges in the +grants config (e.g., select, modify, usage), but MANAGE is not among them. Adding support for this would allow teams to fully automate access control policies for Unity Catalog-managed objects directly within dbt workflows.

### Describe alternatives you've considered

_No response_

### Who will this benefit?

This feature would benefit:

Data platform teams using Databricks Unity Catalog who want to manage access control declaratively.
Organizations with strict governance requirements that need to automate MANAGE privilege assignments.
dbt users looking to reduce manual steps and centralize permission management within dbt projects.

### Are you interested in contributing this feature?

_No response_

### Anything else?

This feature is currently in Public Preview but is already widely used in enterprise environments.