Migrate server to ESM

Sorry for the very big commit that may lead to git log issues and merge
conflicts, but it's a major step forward:

 * Server can be faster at startup because imports() are async and we can
   easily lazy import big modules
 * Angular doesn't seem to support ES import (with .js extension), so we
   had to correctly organize peertube into a monorepo:
    * Use yarn workspace feature
    * Use typescript reference projects for dependencies
    * Shared projects have been moved into "packages", each one is now a
      node module (with a dedicated package.json/tsconfig.json)
    * server/tools have been moved into apps/ and is now a dedicated app
      bundled and published on NPM so users don't have to build peertube
      cli tools manually
    * server/tests have been moved into packages/ so we don't compile
      them every time we want to run the server
 * Use isolatedModule option:
   * Had to move from const enum to const
     (https://www.typescriptlang.org/docs/handbook/enums.html#objects-vs-enums)
   * Had to explictely specify "type" imports when used in decorators
 * Prefer tsx (that uses esbuild under the hood) instead of ts-node to
   load typescript files (tests with mocha or scripts):
     * To reduce test complexity as esbuild doesn't support decorator
       metadata, we only test server files that do not import server
       models
     * We still build tests files into js files for a faster CI
 * Remove unmaintained peertube CLI import script
 * Removed some barrels to speed up execution (less imports)

1 files changed, 135 insertions, 0 deletions

diff --git a/packages/models/src/activitypub/activity.ts b/packages/models/src/activitypub/activity.ts
new file mode 100644
index 000000000..78a3ab33b
--- /dev/null
+++ b/packages/models/src/activitypub/activity.ts
@@ -0,0 +1,135 @@
+import { ActivityPubActor } from './activitypub-actor.js'
+import { ActivityPubSignature } from './activitypub-signature.js'
+import {
+  ActivityFlagReasonObject,
+  ActivityObject,
+  APObjectId,
+  CacheFileObject,
+  PlaylistObject,
+  VideoCommentObject,
+  VideoObject,
+  WatchActionObject
+} from './objects/index.js'
+
+export type ActivityUpdateObject =
+  Extract<ActivityObject, VideoObject | CacheFileObject | PlaylistObject | ActivityPubActor | string> | ActivityPubActor
+
+// Cannot Extract from Activity because of circular reference
+export type ActivityUndoObject =
+  ActivityFollow | ActivityLike | ActivityDislike | ActivityCreate<CacheFileObject | string> | ActivityAnnounce
+
+export type ActivityCreateObject =
+  Extract<ActivityObject, VideoObject | CacheFileObject | WatchActionObject | VideoCommentObject | PlaylistObject | string>
+
+export type Activity =
+  ActivityCreate<ActivityCreateObject> |
+  ActivityUpdate<ActivityUpdateObject> |
+  ActivityDelete |
+  ActivityFollow |
+  ActivityAccept |
+  ActivityAnnounce |
+  ActivityUndo<ActivityUndoObject> |
+  ActivityLike |
+  ActivityReject |
+  ActivityView |
+  ActivityDislike |
+  ActivityFlag
+
+export type ActivityType =
+  'Create' |
+  'Update' |
+  'Delete' |
+  'Follow' |
+  'Accept' |
+  'Announce' |
+  'Undo' |
+  'Like' |
+  'Reject' |
+  'View' |
+  'Dislike' |
+  'Flag'
+
+export interface ActivityAudience {
+  to: string[]
+  cc: string[]
+}
+
+export interface BaseActivity {
+  '@context'?: any[]
+  id: string
+  to?: string[]
+  cc?: string[]
+  actor: string | ActivityPubActor
+  type: ActivityType
+  signature?: ActivityPubSignature
+}
+
+export interface ActivityCreate <T extends ActivityCreateObject> extends BaseActivity {
+  type: 'Create'
+  object: T
+}
+
+export interface ActivityUpdate <T extends ActivityUpdateObject> extends BaseActivity {
+  type: 'Update'
+  object: T
+}
+
+export interface ActivityDelete extends BaseActivity {
+  type: 'Delete'
+  object: APObjectId
+}
+
+export interface ActivityFollow extends BaseActivity {
+  type: 'Follow'
+  object: string
+}
+
+export interface ActivityAccept extends BaseActivity {
+  type: 'Accept'
+  object: ActivityFollow
+}
+
+export interface ActivityReject extends BaseActivity {
+  type: 'Reject'
+  object: ActivityFollow
+}
+
+export interface ActivityAnnounce extends BaseActivity {
+  type: 'Announce'
+  object: APObjectId
+}
+
+export interface ActivityUndo <T extends ActivityUndoObject> extends BaseActivity {
+  type: 'Undo'
+  object: T
+}
+
+export interface ActivityLike extends BaseActivity {
+  type: 'Like'
+  object: APObjectId
+}
+
+export interface ActivityView extends BaseActivity {
+  type: 'View'
+  actor: string
+  object: APObjectId
+
+  // If sending a "viewer" event
+  expires?: string
+}
+
+export interface ActivityDislike extends BaseActivity {
+  id: string
+  type: 'Dislike'
+  actor: string
+  object: APObjectId
+}
+
+export interface ActivityFlag extends BaseActivity {
+  type: 'Flag'
+  content: string
+  object: APObjectId | APObjectId[]
+  tag?: ActivityFlagReasonObject[]
+  startAt?: number
+  endAt?: number
+}