New debug mode:

Debug mode is no more triggered by the NODE_ENV value, but by testing
the existance of a file in the plugin data directory.

server/lib/diagnostic/debug.ts

@@ -0,0 +1,12 @@
+import type { RegisterServerOptions } from '@peertube/peertube-types'
+import { newResult, TestResult } from './utils'
+import { isDebugMode } from '../../lib/debug'
+
+export async function diagDebug (test: string, options: RegisterServerOptions): Promise<TestResult> {
+  const result = newResult(test)
+  result.label = 'Test debug mode'
+  result.ok = true
+  result.messages = [isDebugMode(options) ? 'Debug mode is ON' : 'Debug mode is OFF']
+  result.next = 'webchat-video'
+  return result
+}