fix: Handles resource deletion in ReadResource

[EspenAlbert]

Description

Handles resource deletion in ReadResource. Terraform informs you about the resource deleted outside of Terraform, and the plan will re-create the resource

Link to any related issue(s): CLOUDP-248670

Type of change:

• [ ] Bug fix (non-breaking change which fixes an issue). Please, add the "bug" label to the PR.
• [ ] New feature (non-breaking change which adds functionality). Please, add the "enhancement" label to the PR. A migration guide must be created or updated if the new feature will go in a major version.
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected). Please, add the "breaking change" label to the PR. A migration guide must be created or updated.
• [ ] This change requires a documentation update
• [ ] Documentation fix/enhancement

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• [x] I have signed the MongoDB CLA
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• [x] I have checked that this change does not generate any credentials and that they are NOT accidentally logged anywhere.
• [x] I have added tests that prove my fix is effective or that my feature works per HashiCorp requirements
• [x] I have added any necessary documentation (if appropriate)
• [x] I have run make fmt and formatted my code
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Further comments

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[EspenAlbert]

Only OUT_OF_CAPACITY failure in the test so merging