Add is_allocated to all appropriate view like containers

[jeffmiles63]

Added is_allocated function to the following classes and unit tests:
Kokkos::View
Kokkos::DualView
Kokkos::DynRankView
Kokkos::DynamicView
Kokkos::Vector
Kokkos::BitSet
Kokkos::OffsetView
Kokkos::ScatterView
Kokkos::StaticCrsGraph
Kokkos::UnorderedMap
Kokkos::Array

Part of issue #3024

[codecov-commenter]

Codecov Report

Merging #3059 into develop will increase coverage by 0.1%.
The diff coverage is 100.0%.

@@            Coverage Diff            @@
##           develop   #3059     +/-   ##
=========================================
+ Coverage     82.6%   82.7%   +0.1%     
=========================================
  Files          122     122             
  Lines         8074    8126     +52     
=========================================
+ Hits          6673    6725     +52     
  Misses        1401    1401             

Flag	Coverage Δ
#clang	81.5% <100.0%> (+<0.1%)	⬆️
#gcc	83.0% <100.0%> (+0.1%)	⬆️

Impacted Files	Coverage Δ
containers/src/Kokkos_DynRankView.hpp	92.3% <ø> (ø)
core/src/Kokkos_Array.hpp	100.0% <ø> (ø)
containers/src/Kokkos_Bitset.hpp	92.8% <100.0%> (+0.1%)	⬆️
containers/src/Kokkos_DualView.hpp	77.4% <100.0%> (+0.3%)	⬆️
containers/src/Kokkos_DynamicView.hpp	88.8% <100.0%> (+1.1%)	⬆️
containers/src/Kokkos_OffsetView.hpp	95.6% <100.0%> (+0.1%)	⬆️
containers/src/Kokkos_ScatterView.hpp	91.7% <100.0%> (+0.4%)	⬆️
containers/src/Kokkos_StaticCrsGraph.hpp	96.5% <100.0%> (+0.2%)	⬆️
containers/src/Kokkos_UnorderedMap.hpp	97.6% <100.0%> (+<0.1%)	⬆️
containers/src/Kokkos_Vector.hpp	81.3% <100.0%> (+0.4%)	⬆️
... and 8 more

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[dalg24]

I don't think we should add is_allocated to Kokkos::Array.

[crtrott]

definitely not to Array.

[crtrott]

Retest this please.

[crtrott]

@jeffmiles63 can you add documentation (you can do it on the public wiki)