##Summary
This PR refactors js/blocks/RhythmBlockPaletteBlocks.js by extracting duplicated setTimeout-based note scheduling logic from:
-RhythmBlock.flow
-Tuplet4Block.flow

##Problem

Both RhythmBlock and Tuplet4Block implemented nearly identical logic to:
-Loop through beat values
-Compute beat duration using bpmFactor
-Schedule notes using setTimeout
-Handle final cleanup callback
-Call tur.doWait(...)

This duplication:
-Violates DRY principles
-Makes future timing fixes harder
-Increases risk of inconsistent behavior
-Complicates testing and maintenance

##Changes
[NEW]
Add playNoteSequence(activity, beatValues, blk, turtle, bpmFactor, onComplete) helper function to centralize note scheduling logic.

Responsibilities:
-Calculate beat duration
-Schedule notes using setTimeout
-Handle final callback
-Perform tur.doWait timing synchronization