Backport to release-14: Fix VTOrc Discovery to also retry discovering tablets which aren't present in database_instance table

[GuptaManan100]

Description

This PR is a backport of #10662 to releaes-14.0

Related Issue(s)

• Bug Report: VTOrc does not discover tablets if the durability policy is not set initially #10650

Checklist

• "Backport me!" label has been added if this change should be backported
• Tests were added or are not required
• Documentation was added or is not required

Deployment Notes

[vitess-bot]

Review Checklist

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