[EASI-4527] add presentation links schema

[mynar7]

EASI-4527

Description

• Adds GraphQL and DB schema for GRB presentation links

How to test this change

• N/A

PR Author Checklist

• I have provided a detailed description of the changes in this PR.
• I have provided clear instructions on how to test the changes in this PR.
• I have updated tests or written new tests as appropriate in this PR.

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[github-actions]

EKS Ingress URLs

• EASi
• Mailcatcher
• Minio Console

[samoddball]

meant to re-approve yesterday - sorry Lee