RFR: 8374219: Fix issues in jpackage's Executor class

[Alexey Semenyuk]

On Wed, 10 Dec 2025 05:03:47 GMT, Alexey Semenyuk <asemenyuk at openjdk.org> wrote:

> - Move code shared between jpackage's Executor and jpackage's test lib Executor into `jdk.jpackage.internal.util.CommandOutputControl` class using the latter one as the baseline for the new class; [CommandOutputControl class javadoc](https://alexeysemenyukoracle.github.io/jpackage-javadoc/jdk.jpackage/jdk/jpackage/internal/util/CommandOutputControl.html).
> - Place "execute with retries" logic into `jdk.jpackage.internal.util.RetryExecutor` class and use it from both jpackage and jpackage's test lib. Use `jdk.jpackage.internal.RetryExecutor` class as the baseline.
> - Add `ObjectFactory`, `ExecutorFactory`, and `RetryExecutorFactory` interfaces to the "jdk.jpackage.internal" package. They enable the use of command mocks with jpackage.
> - Add `jdk.jpackage.test.mock` package. It facilitates creating command mocks. Use it to test LibProvidersLookup, LinuxSystemEnvironment, LinuxPackageArch, MacDmgSystemEnvironment, and MacDmgPackager classes.
> 
> Supplementary changes:
>  - Make `jdk.jpackage.internal.SystemEnvironment` and all implementing classes package private

@sashamatveev PTAL

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PR Comment: https://git.openjdk.org/jdk/pull/28733#issuecomment-3706191311