4.x: Rename all `rx4.` properties configuring the library into `rxjava4.`

[akarnokd]

So that when the next rename comes, we don't need to search/replace all the rx4. -> rx5. in the code and docs.

[bhja]

hi @akarnokd -
Would openrewrite suit your needs for this . I think it would fit well for code.

https://docs.openrewrite.org/recipes/text/findandreplace

[akarnokd]

@bhja Do it, don't suggest a tool. I can do it manually, but people complain they are left with nothing to contribute.

[bhja]

@bhja Do it, don't suggest a tool. I can do it manually, but people complain they are left with nothing to contribute.

Sure, I can do it manually but the brief above seemed like automating it for ease in the future. Let me know which way and I will get started.

For instance - Constants in the code refer to rx4 currently like the one below.

static final String KEY_MAX_THREADS = "rx4.computation-threads"; line no 39 in ComputationScheduler.java

[akarnokd]

No need to automate. We do it every once 5 years by hand.

Please post a PR with the changes, do not keep asking for "clarifications".

Turn rx4. into rxjava4. while checking you do not introduce weird space or character deletions.

[akarnokd]

@bhja is now banned from this repo. Spent more time arguing how I should do it vs doing it himself.

I don't need people "thinking" for me or the project. We need people looking at the various issues, then creating a PR that resolves that issue. If you keep asking "clarification" question, that is no better than me doing the task by myself.