Oss resource graph queries

[mspetroula]

Overview/Summary

Replace this with a brief description of what this Pull Request fixes, changes, etc.

Related Issues/Work Items

Replace this with a list of related GitHub Issues and/or ADO Work Items (Internal Only)

N.A

This PR fixes/adds/changes/removes

1. Update to psql-2.kql provided query for custom maint window
2. Update to myql-1.kql provided query for Zone redundant HA
3. Update to myql-2.kql provided query for custom maint window
4. Update to db-for-postgresql/_index.md set ARG Query available for psql-2
5. Update to db-for-mysql/_index.md set ARG Query available for myql-1 and myql-2

As part of this Pull Request I have

• [x ] Read the Contribution Guide and ensured this PR is compliant with the guide
• [ x] Checked for duplicate Pull Requests
• Associated it with relevant GitHub Issues or ADO Work Items (Internal Only)
• [x ] Ensured my code/branch is up-to-date with the latest changes in the main branch
• [x ] Ensured PR tests are passing
• Performed testing and provided evidence (e.g. screenshot of output) for any changes associated to ARG queries and/or scripts
• Updated relevant and associated documentation (e.g. Contribution Guide, Docs etc.)

[ejhenry]

Thanks for the contribution @mspetroula! Please include screenshots of the successful testing of your ARG queries in the PR.

[mspetroula]

    

[ejhenry]

LGTM