workflow adjustment

[Songtronix]

This will remove the need of the staging branch. Therefore by default work is being done on master and such is not recommended to be used. Always use the latest release in production.

For more details view the PACKAGING.md or WORKFLOW.md

Furthermore it cherry picks alot of fixes to be released under 0.4.3 soon. Here are the changes:

Added

• add troubleshooting guide
• create server image tagged with branch or tag automatically

Changed

• serve veloren locally (removes s3 support)

Fixed

• Gitlab Pipeline Event model
• CI not running on forks
• quote paths in msiexec call
• validate response status before download
• only use one rustfmt.toml
• leave one artifact per os on prune
• reduced minimum window size
• check status of webhook response