CAMEL-19986-1: Improved ThrottlingExecutor

[LostArtist]

Improved ThrottlingExecutor, so it can execute more different tasks.
Usage:

slowly().repeat(count_of_repetitions).awaiting(interval, TimeUnit.MILLISECONDS).beforeWait()
                .beforeEach((i) -> task1)
                .afterEach((i) -> task2)
                .execute();

[github-actions]

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[orpiske]

LGTM and it looks quite straight to the point.

Ideally, on a subsequent PR, you could provide some javadoc to the public APIs.