Add transient test cases for mori and immutable

mori and immutable support transient intermediate tries as a
performance optimization (mori calls this freeze/thaw, immutable calls
this immutable/mutable). This adds test cases illustrating the
performance differences when transience is used.
Merge branch 'leebyron-transients'
Splitting transient tests into own tests, adding support for hamt_plus
Added hamt+ results for all benchmarks