Fix code scanning alert - Missing rate limiting

[sudocode1]

Tracking issue for:

• https://github.com/DefinityTeam/vapour/security/code-scanning/6
• https://github.com/DefinityTeam/vapour/security/code-scanning/5
• https://github.com/DefinityTeam/vapour/security/code-scanning/4
• https://github.com/DefinityTeam/vapour/security/code-scanning/3
• https://github.com/DefinityTeam/vapour/security/code-scanning/2
• https://github.com/DefinityTeam/vapour/security/code-scanning/1

These security issues should be patched as soon as possible to prevent DDoS (whether intentional or unintentional) attacks on containers and the launcher.

A lot of this can be fixed by simply reading file contents when the server is started, rather than reading them every time. I will issue a patch for this soon.