Mc/camelize directives

[michaelcaterisano]

We're using custom schema directives in an Apollo federated schema. I noticed that multi-word directives were showing up as snake_case in the schema rather than camelCase. The change to notation.ex took care of camelCasing directives as defined in the sdl_render_test.exs, but the additional change in sdl_render.ex seemed to be necessary to camelCase custom schema directives defined in a federated subgraph. I'm not sure how to test that here since defining them relies on Apollo's composeDirective directive:

  extend schema do
    directive(:link, url: "https://specs.apollo.dev/federation/v2.5", import: ["@composeDirective"])
    directive(:link, url: "https://some-url.com", import: ["@disallowedForSubscriptions"])
    directive(:composeDirective, name: "@disallowedForSubscriptions")
  end

Any feedback would be appreciated cc: @benwilson512

[benwilson512]

This looks good to me, thanks!

[michaelcaterisano]

@benwilson512 I assumed the tests would run in CI; I just ran the whole suite locally and it seems this broke some tests, specifically strict_schema_test.exs. I'm going to take a look now and see if I can figure out why they're failing. Feel free to revert if necessary while I look into it.