Package installations should not override existing Vector configs

[binarylogic]

As part of our new installation instructions, we want users to configure Vector before installing it. This avoids the following confusing situation:

1. User installs Vector
   1. Vector starts automatically after being installed with our stock config.
   2. Vector starts polluting logs.
2. Configure Vector
3. Start Vector
   1. User encounters an "already running" error.
   2. Or worse, nothing is printed since Vector is already running and the user thinks they started Vector with their config.
4. User thinks Vector is running with their config but it is not.

Requirements

As a result we need to:

• Ensure our .deb package does not overwrite an existing vector.toml file.
• Ensure our .rpm package does not overwrite an existing vector.toml file.
• Ensure our nix package does not overwrite an existing vector.toml file.
• Ensure our .msi package does not overwrite an existing vector.toml file.