bug(gatsby-source-strapi): Relations are not picked up if they are named "parent" or "children"

[denisgoryaynov]

Since "parent" and "children" are reserved keywords in gatsby, this plugin automatically appends "strapi_" to the relation name. Since the relations are now named "strapi_parent" and "strapi_children" the code on this line doesn't work, https://github.com/strapi/gatsby-source-strapi/blob/2a60320b16ae6520617d743158c433d384dbd155/src/download-media-files.js#L117, since the relations on the strapi schema are named just "parent" and "children", but attributeName is "strapi_parent" and "strapi_children".
This problem is related to the other issue I have with relations: gatsby-uc/gatsby-source-strapi#308, because without changing the code to schema.schema.attributes[attributeName.replace('strapi_', '')] the fix I illustrated in the other issue doesn't work because the fields generated from this plugin and the schema on strapi are different

[soupette]

@denisgoryaynov the parent and children names are forbidden in gatsby this is why we prefixed them with strapi_ same for the id field.

[denisgoryaynov]

Hi @soupette, I understand that those names are forbidden in gatsby and that's why they are prefixed with strapi_, the problem is that this change is not reflected when getting the data from the strapi schema when downloading images.
Inside this line of code const attribute = schema.schema.attributes[attributeName]; the schema.schema.attributes has the children and parent fields (because it is fetched from the content builder api), but they are accessed using the prefixed fields strapi_children and strapi_parent, thus returning undefined every time

[soupette]

Hi @soupette, I understand that those names are forbidden in gatsby and that's why they are prefixed with strapi_, the problem is that this change is not reflected when getting the data from the strapi schema when downloading images. Inside this line of code const attribute = schema.schema.attributes[attributeName]; the schema.schema.attributes has the children and parent fields (because it is fetched from the content builder api), but they are accessed using the prefixed fields strapi_children and strapi_parent, thus returning undefined every time

You are right! it's a bug indeed, would you mind opening a PR to fix the issue so we can make a new release?