fix: retain array dtype in filter operations and avoid first() on empty results

[shayann07]

Resolves #221

Addresses maintainer feedback from @devcrocod on empty collection handling and type inference across multidimensional array operations:

1. Retain dtype on empty filter/slice results:

   • ilter, ilterIndexed, ilterMultiIndexed, ilterNot, distinctBy, groupBy, and partition in IteratingNDArray.kt now preserve his.dtype when predicates match zero elements instead of invoking DataType.of(list.first()) (which threw NoSuchElementException).
   • dropWhile now returns an empty array with his.dtype when all elements are dropped instead of throwing an error.

2. Dtype resolution in flatMap:

   • latMap, latMapIndexed, and latMapMultiIndexed resolve dtype via DataType.ofKClass(R::class) using reified type parameters so that empty results retain their target data type.

3. Safe constructor dimension calculation and JS type inference:

   • Primitive 2D array constructors in primitiveArrays.kt safely handle empty outer arrays without indexing element 0.
   • In constructors.kt (
     darrayCommon), when an explicit dtype is provided, type inference avoids inspecting elements.first(), fixing incorrect type inference on Kotlin/JS.

Added tests in IterableNDArrayTest.kt and ErrorHandlingTest.kt covering empty and non-empty results across all data types (Int, Double, Float, Long, Byte, Short, ComplexFloat, ComplexDouble), verifying clean passes on JVM, Native (MingwX64), and JS/WasmJS.

[shayann07]

Closing for now so the approach can be discussed in #221 first.