Adding follow requests API

app/controllers/api/v1/follow_requests_controller.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+class Api::V1::FollowRequestsController < ApiController
+  before_action -> { doorkeeper_authorize! :follow }
+  before_action :require_user!
+
+  def index
+    results   = FollowRequest.where(target_account: current_account).paginate_by_max_id(DEFAULT_ACCOUNTS_LIMIT, params[:max_id], params[:since_id])
+    accounts  = Account.where(id: results.map(&:account_id)).map { |a| [a.id, a] }.to_h
+    @accounts = results.map { |f| accounts[f.account_id] }
+
+    set_account_counters_maps(@accounts)
+
+    next_path = api_v1_follow_requests_url(max_id: results.last.id)    if results.size == DEFAULT_ACCOUNTS_LIMIT
+    prev_path = api_v1_follow_requests_url(since_id: results.first.id) unless results.empty?
+
+    set_pagination_headers(next_path, prev_path)
+  end
+
+  def authorize
+    FollowRequest.find_by!(account_id: params[:id], target_account: current_account).authorize!
+    render_empty
+  end
+
+  def reject
+    FollowRequest.find_by!(account_id: params[:id], target_account: current_account).reject!
+    render_empty
+  end
+end