fix(protonvpn): support port 51820 for UDP OpenVPN

fix(slickvpn): add missing servers found online

fix(purevpn): update openvpn configuration

- Credits to @mlapaj
- Taken and verified from #2991

fix(proton): giving proton password is not mandatory

feat(protonvpn): update servers data including paid data

fix(protonvpn): authenticated servers data updating (#2878)

- `-proton-username` flag for cli update
- `-proton-password` flag for cli update
- `UPDATER_PROTONVPN_USERNAME` option for periodic updates
- `UPDATER_PROTONVPN_PASSWORD` option for periodic updates

feat(firewall): support icmp rules

feat(server): role based authentication system (#2434)

- Parse toml configuration file, see https://github.com/qdm12/gluetun-wiki/blob/main/setup/advanced/control-server.md#authentication
- Retro-compatible with existing AND documented routes, until after v3.41 release
- Log a warning if an unprotected-by-default route is accessed unprotected
- Authentication methods: none, apikey, basic
- `genkey` command to generate API keys
- move log middleware to internal/server/middlewares/log

Co-authored-by: Joe Jose <45399349+joejose97@users.noreply.github.com>

fix(version): log last release by tag name alphabetically instead of …

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fix(version): log last release by tag name alphabetically instead of …

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