feat: add dataset delete endpoint

[perzeuss]

Description

The Knowledge API currently supports the creation of Knowledges/Datasets but it does not support the deletion of Knowledges/Datasets. This PR adds the ability to delete Knowledges/Datasets.

This change has already been merged to the dev environment and can be tested there, see #5035

Type of Change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

I tested it manually with postman and curl.

• Create an empty dataset e.g. with this command:

curl --location --request POST 'http://127.0.0.1:5001/v1/datasets' \
--header 'Authorization: Bearer {api_key}' \
--header 'Content-Type: application/json' \
--data-raw '{"name": "I can delet this via api"}'

• Delete the dataset with this command:

curl --location --request DELETE 'http://127.0.0.1:5001/v1/datasets/{dataset_id}' \
--header 'Authorization: Bearer {api_key}'

Suggested Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods
• optional I have made corresponding changes to the documentation
• optional New and existing unit tests pass locally with my changes