Added Kokkos metadata callback

[DavidPoliakoff]

This adds a callback to Caliper for Kokkos metadata. Note that we guard this with Adiak not being defined, if we have Adiak we'll declare metadata there (link to that PR: LLNL/Adiak#6 ). We should wait on the Adiak PR to merge this, if we do decide to merge this

[codecov]

Codecov Report

Merging #335 (56b3859) into master (ace283d) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #335   +/-   ##
=======================================
  Coverage   83.54%   83.54%           
=======================================
  Files         150      150           
  Lines       11015    11015           
=======================================
  Hits         9202     9202           
  Misses       1813     1813           

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