BO21 - Create a DAL function to add a Sponsor

[gregoriopalama]

Add a DAL function in the Sponsorship API.

The function accept contain the informations about the sponsor:

• sponsorshipID. This is required;
• name. This is required;
• link. This is required;
• position: this will be checked. If there is an other sponsor with the same position, the other one will be updated and moved to the next position, and the same will be done for any other level with a colliding position. This field is optional. If not provided, the position will be set to the actual number of sponsors in the db (index must start from 0).

The response will be an error if something goes wrong. Otherwise, the function will provide the inserted sponsor object in the response's body, including the ID of the document in the DB.

Depends on #182

[giacomoRanieri]

I'll try resolving this issue.
I need just a small clarification.

I recon that the "Also" part may require a multipart form data to be able to also upload the image.
Does this mean that:

• the body is always a multipart?
• the json part of the body has key "body" ?
• the file part of the body has key "image" ?

[gregoriopalama]

Thanks for asking @giacomoRanieri .
First of all, I've updated the issue's description to reflect the fact that this depends on #182 : we need the endpoint on the sponsorships levels, before we can work on this.

@camillobucciarelli I think we should discuss Giacomo's doubts asap and provide a proper answer

[gregoriopalama]

@giacomoRanieri again, thanks for your questions.
We've discussed this internally and updated the issue accordingly: the image will be handled solely with the appropriate endpoint, keeping this one very simple. The PUT action on the image endpoint, making it idempotent, will reflect the meaning of it: the image will be "overwritten" everytime, by deleting the old one from the storage, uploading the new one and updating the image url in the firestore document

[giacomoRanieri]

I'll wait for #182 to be completed to work on this :)