Add fail2ban to improve security

[OniriCorpe]

Problem

• the package lacks fail2ban, which makes it easy to bruteforce user password

Solution

• adding fail2ban config to detect failed login attempts

PR Status

• [x] Code finished and ready to be reviewed/tested
• [x] The fix/enhancement were manually tested (if applicable)

[OniriCorpe]

tested successfully (i got banned after 5 failed logins 🥲)

2023-09-10 22:58:39,332 fail2ban.filter         [1874]: INFO    [gotosocial__2] Found 198.51.100.0 - 2023-09-10 22:57:46
2023-09-10 22:58:43,580 fail2ban.filter         [1874]: INFO    [gotosocial__2] Found 198.51.100.0 - 2023-09-10 22:57:46
2023-09-10 22:58:47,608 fail2ban.filter         [1874]: INFO    [gotosocial__2] Found 198.51.100.0 - 2023-09-10 22:58:47
2023-09-10 22:58:51,882 fail2ban.filter         [1874]: INFO    [gotosocial__2] Found 198.51.100.0 - 2023-09-10 22:58:47
2023-09-10 22:58:55,591 fail2ban.filter         [1874]: INFO    [gotosocial__2] Found 198.51.100.0 - 2023-09-10 22:58:47
2023-09-10 22:58:56,320 fail2ban.actions        [1874]: NOTICE  [gotosocial__2] Ban 198.51.100.0
2023-09-10 22:58:56,373 fail2ban.filter         [1874]: INFO    [recidive] Found 198.51.100.0 - 2023-09-10 22:58:56

(IP is redacted)