This adds a new feature to build a dependency graph of Pkl programs, following the SPICE outlined in https://github.com/apple/pkl-evolution/pull/2.
It adds:
* CLI command `pkl analyze imports`
* Java API `org.pkl.core.Analyzer`
* Pkl stdlib module `pkl:analyze`
* pkl-gradle extension `analyze`
In addition, it also changes the Gradle plugin such that `transitiveModules` is by default computed from the import graph.
Adds a `rename` field to the Java/Kotlin code generators that allows renaming packages and classes during codegen.
* Add `--rename` flag to CLIs
* Add `rename` property to Gradle API
* Add `--proxy` and `--no-proxy` CLI flags
* Add property `http` to `pkl:settings`
* Move `EvaluatorSettings` from `pkl:Project` to its own module and add property `http`
* Add support for proxying in server mode, and through Gradle
* Add `setProxy()` to `HttpClient`
* Add documentation
