New option to use and configure Prosody mod_firewall WIP (#97):

* new setting
* new configuration screen for Peertube admins
* include the mod_firewall module
* load mod_firewall if enabled
* sys admin can disable the firewall config editing by creating a
  special file on the disk
* user documentation

shared/lib/admin-firewall.ts

@@ -0,0 +1,12 @@
+// SPDX-FileCopyrightText: 2024 John Livingston <https://www.john-livingston.fr/>
+//
+// SPDX-License-Identifier: AGPL-3.0-only
+
+// Note: API request body size is limited to 100Kb (expressjs body-parser defaut limit, and Peertube nginx config).
+// So we must be sure to never send more than 100Kb.
+// All files are sent in one JSON object.
+export const maxFirewallFileSize: number = 3 * 1024
+export const maxFirewallFiles = 20
+
+export const maxFirewallNameLength = 20
+export const firewallNameRegexp = /^[a-zA-Z0-9_-]+$/