Update security settings

[tgranqvist]

Update the security settings to give better ratings:

• cipher suites
• protocol versions
• headers

Testing:

• SSL Labs should give A+ rating
• Security Headers should give A rating

[tgranqvist]

Added dynamic TLS config for Traefik in /etc/traefik/security.yaml:

• Minimum TLS version 1.2
• Secure ciphers

Now [scores A+] on ssl-test

[tgranqvist]

Added HTTP header configuration in /etc/traefik/security.yaml

• SSL Redirect
• Frame Options
• HSTS
• Content Type Options

Went up from F to C on Security Headers test.

Still need to check the impact of e.g. CSP header and include all resources.