[DOC-793] Modify schema review workaround pages for Oracle and MySQL (#28671)

* oracle restructure done

* reorg known issues

* missed changes

* intro

* Apply suggestions from code review

Co-authored-by: Dwight Hodge <[email protected]>

* review comments

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Co-authored-by: Dwight Hodge <[email protected]>

Author: aishwarya24