Please add version in the package name only when necessary

For now, debcargo adds version into every package name. For example, one of the dependency of ripgrep is "librust-encoding-rs-0.7+default-dev" this should be called instead "librust-encoding-rs+default-dev"

For several reasons:

• it is going to be impossible to maintain properly rust packages in the archive if we have X versions of the same libraries. We had to do that for Java, it isn't fun at all...
• this will requires to go throught NEW for every new version
• security issues management will be a huge pain as we will have to backport to all instances of the packages
• backports will be a pain too

Probably more