fix(fetch): use fetch provided by load function when available

src/routes/+page.js

src/routes/articles/+page.js

src/routes/articles/[slug]/+page.js

src/routes/authors/+page.js

src/routes/authors/[_id]/+page.js

src/routes/groups/+page.js

src/routes/groups/[slug]/+page.js

src/routes/structures/+page.js

src/routes/structures/[_id]/+page.js

src/routes/structures/[_id]/articles/+page.js

src/routes/structures/[_id]/authors/+page.js

src/utils/api/methods.js