Add priority to transcoding jobs

(1 = highest priority)

100 for new resolutions
10 for original file optimization

Add a malus for transcoding jobs depending on how many uploads the user did in the
last 7 days

server/lib/job-queue/job-queue.ts

@@ -47,6 +47,7 @@ type CreateJobArgument =
 
 type CreateJobOptions = {
   delay?: number
+  priority?: number
 }
 
 const handlers: { [id in JobType]: (job: Bull.Job) => Promise<any> } = {
@@ -148,6 +149,7 @@ class JobQueue {
       backoff: { delay: 60 * 1000, type: 'exponential' },
       attempts: JOB_ATTEMPTS[obj.type],
       timeout: JOB_TTL[obj.type],
+      priority: options.priority,
       delay: options.delay
     }