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, 27 insertions, 0 deletions

diff --git a/packages/tests/tsconfig.json b/packages/tests/tsconfig.json
new file mode 100644
index 000000000..91a74b4be
--- /dev/null
+++ b/packages/tests/tsconfig.json
@@ -0,0 +1,27 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "./dist",
+    "baseUrl": "./",
+    "rootDir": "src",
+    "tsBuildInfoFile": "./dist/.tsbuildinfo",
+    "paths": {
+      "@tests/*": [ "src/*" ]
+    }
+  },
+  "references": [
+    { "path": "../core-utils" },
+    { "path": "../ffmpeg" },
+    { "path": "../models" },
+    { "path": "../node-utils" },
+    { "path": "../typescript-utils" },
+    { "path": "../server-commands" },
+    { "path": "../../server/tsconfig.lib.json" }
+  ],
+  "include": [
+    "./src/**/*.ts"
+  ],
+  "exclude": [
+    "./fixtures"
+  ]
+}