Add CreateComponent mutation to allow components to be added to a project

[patch0]

This should allow a mutation like

mutation($projectId: String!, ...) {
    createComponent(input: {projectId: $projectId, ...}) {
      component {
        id
    }
  }
}

with suitable inputs, i.e. projectId, name, extension etc.

[create-issue-branch]

Branch issues/149-Add_CreateComponent_mutation_to_allow_components_to_be_added_to_a_project created!