Only copy bedrock_server executable on update

What does this MR do and why?

Fix bug where bedrock update would overwrite custom user setups with all predefined bedrock parameters. This would occur due to the fact that we'd inflate the entire archive and overwrite each file in the server directory when all we wanted was to omit certain files like server.properties and allowlist.json, etc.

Resolves #208 (closed)

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• Have you checked this doesn't interfere/conflict/duplicate someone elses work?
• Have you fully tested your changes?
• Have you resolved any lint issues?
• Have you assigned a reviewer?
• Have you applied correct labels?