Note: This is not final version. This requires to create config file
and set properly suricata config

Issue https://gitlab.labs.nic.cz/turris/turris-os-packages/issues/358

- Disable geoip2 for now.
Libmaxminddb is required, but there are some compile issues for Turris 1.x.
Which are not present in Turris OS 4.x/5.x.
- Disable snmp dest
Will enable on request

Fixes: #412

Changes:
-config cleanup
-add functions.sh for common function used in DOT
-update readme

Fix private key permissions

- Add : to variant
- Corrected SPDX License Identifier

And configure restart proxy hook

- Rename Certgen binary
- Update to version 6.1
  - Wait delay limits
  - Hooks directory
  - Private key permissions

CA certificate is used by Sentinel:Proxy itself and in fact,
Sentinel:Certgen does not know anything about MQTT server which Proxy
communicates with and has certificate signed by this CA

Changes:
-add polishing from https://github.com/openwrt/packages/pull/9223
-add PKG_BUILD_DEPENDS with setuptools