Create the GraphQL endpoint for SetPermissionsForBitbucketProject and enqueue the job

Created by: asdine

Here is an attempt to write the GraphQL API. Feel free to modify if not correct.

mutation SetPermissionsForBitbucketProject(
    $projectKey: String!,
    $codeHostID: String!, # base64 version of the external service id
    $permissions: [Permission!],
    $unrestricted: bool,
) {
    alwaysNil
}

type Permission {
    bindID: String!
}