oracle, mssql, redshift templates

[neelasha23]

Describe your changes

Added DB templates for Oracle, Microsoft SQLServer and Redshift

Issue number

Closes #72

Checklist before requesting a review

• [ ] Performed a self-review of my code
• [ ] Formatted my code with pkgmt format
• [ ] Added tests (when necessary).
• [ ] Added docstring documentation and update the changelog (when needed)

[neelasha23]

Added UI tests. Please review @edublancas