feat(effects): accept ObservableInput as concatLatestFrom argument

[benlesh]

• removes identity use of pipe(fn).
• removes use of of(x).pipe(withLatestFrom(...args))) in favor of just forkJoin(args).pipe(map(r => [x, ...r])) because it's more efficient and does basically the same thing.
• No longer checks to see if there's an array
• Changes the typings to use ObservableInput rather than Observable. The code always supported Promise, Iterable, AsyncIterable, etc, but the TypeScript typings prevented it.

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/ngrx/platform/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Documentation has been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[x] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[x] Other... Please describe: Fixed the types

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

This is a refactor with the exception of type changes. Sort of a drive-by on my part because someone pointed me to this operator during an interview. If y'all want to add type changes or have someone take this PR over and run with it, that's fine.

I made this PR with the GitHub online IDE. I have no idea if CI will pass.

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[benlesh]

Looking at this, I just reverted to remove the superfluous pipe call. It's mostly fine, but it feels like this could be more efficient.

Sorry for the churn BTW, the GitHub Web API isn't amazing for iterating on development, and I didn't feel like setting things up locally.

Basically, I'd really need to understand the use-cases here, because it seems expensive to have to subscribe to N observables for each dispatched action. What I suspect is that most of the use cases this is serving would be better served by a more specialized set of code, but I don't have context. For example though, if I were to see that most of the use cases for this were selecting a current value from state, I'd say that it would be better to synchronously just pull that value from state with a simple function call rather than subscribe to a push... Which is the difference between of(x) and function value() { return x; }... the latter is less "work".

In any case, that additional pipe isn't needed.

[brandonroberts]

There's context related to why we introduced concatLatestFrom here #2222.

On the development side of things, we also have built-in support for using GitHub codespaces in this repo, so you can still edit on the web with a better interface.

https://github.com/ngrx/platform/blob/master/CONTRIBUTING.md