Allow JavaProvider(java_common.provider) to expose transitive_compile_time_jars (for scala strict deps)

[natansil]

We are in the process of adding a strict deps feature for rules_scala (issue).

In order to complete this feature we would like for javaProvider (java_common.provider) to expose transitive_compile_time_jars.
(Currently JavaProvider only exposes transitive_runtime_jars and compile_jars)

This will allow us to alert the build user that there transitive dependencies that should be added to direct dependencies.

[laszlocsomor]

Asking @laurentlb to help triage this: is this a Skylark feature request, or a Java rule one?

[dslomov]

Java rules /cc @iirina

[natansil]

Thanks @iirina!
Do you know when is the next scheduled release of bazel?

[buchgr]

We are trying to cut the first release candidate of 0.5.3 as we speak.