Rename core lib crates to have 'graphite' prefix

[protheory8]

Someone might want to make a third-party GUI implementation for Graphite. To do that they would need to link to core libs that we have in packages directory, so I think we should consider publishing them to https://crates.io at some point in the future. However before we can do that we need to rename crates to have a unique name.

I suggest we name crates cli and render-engine to graphite-cli and graphite-render-engine respectively. To do that we only need to change the name field in Cargo.toml, no need to rename directories.

[protheory8]

We probably also should put publish = false on crates that aren't supposed to be published.