fix(database): Add missing `dbname` parameter to PostgreSQL DSN connection string

### Current Behavior
Currently, in `database/database.go`, the PostgreSQL DSN is constructed without including the `dbname` parameter, which may lead to connection issues or default database usage.

### Expected Behavior
The PostgreSQL DSN should explicitly include the `dbname` parameter to ensure the application connects to the intended database correctly.

### Contributor [Guides](https://docs.meshery.io/project/contributing) and [Handbook](https://meshery.io/community#handbook)
- 🛠 [Meshery Build & Release Strategy](https://docs.meshery.io/project/contributing/build-and-release)
- 📚 [Instructions for contributing to documentation](https://github.com/meshery/meshery/blob/master/CONTRIBUTING.md#documentation-contribution-flow)
- Meshery documentation [site](https://docs.meshery.io/) and [source](https://github.com/meshery/meshery/tree/master/docs)
- 🎨 Wireframes and [designs for Meshery UI](https://www.figma.com/file/SMP3zxOjZztdOLtgN4dS2W/Meshery-UI) in Figma [(open invite)](https://www.figma.com/team_invite/redeem/GvB8SudhEOoq3JOvoLaoMs)
- 🙋🏾🙋🏼 Questions: [Discussion Forum](http://discuss.meshery.io) and [Community Slack](https://slack.meshery.io)

Start in database/database.go and inspect how the PostgreSQL DSN connection string is assembled. Confirm the available database name value and ensure the resulting DSN includes it as the dbname parameter. Done means connections target the intended PostgreSQL database rather than relying on a default.

Written by the indexing model from the issue text.