This reduces if block nesting similar to how we did it in #15250 (which got lost during the await feature introduction): If the if expression doesn't contain an await expression or is not dependent on a blocker that is not already resolved, then we can avoid creating a separate $.if() statement. The one trade-off is that we'll do re-invocations for all the conditions leading up to the condition that matches. Therefore non-simple if expressions are wrapper in $.derived to avoid excessive recomputations.

closes #17659 (~320 markers in prod mode possible now; less in dev because of our "wrap this component with devtime info" method) helps with #15200

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