In the replacement arg of gsub() the & symbol is a special character
that need to be escaped. To avoid this, and further issues due to the
variable name possibly being interpreted as a regex, we do a normal
substring replacement.
This fixes issues #279803.
At this point this is basically a full rewrite of this module, which
is a breaking change and was necessary to properly expose the useful
parts of hostapd's config. The notable changes are:
- `hostapd` is now started with additional systemd sandbox/hardening options
- A single-daemon can now manage multiple distinct radios and BSSs, which is
why all configuration had to be moved into `hostapd.radios`
- By default WPA3-SAE will be used, but WPA2 and WPA3-SAE-TRANSITION are
supported, too
- Added passwordFile-like options for wpa and sae
- Add new relevant options for MAC ACL, WiFi5, WiFi6 and WiFi7 configuration
- Implements RFC42 as far as reasonable for hostapd
- Removes `with lib;`
