[code-reflection] Integrated: Simplified maven copy to build dir

[Gary Frost]

Maven + CMake  used to create shared libs (backends) in local `cmake-debug-build` dir under each backend and copy to common top level `build` 

Now we create the `cmake-debug-build` in the top level `build` directly.  The unnecessary copy has been removed. 

This aligns with how the bld script works. 

Also both maven and bld populate the same dir.  

I fixed up all docs and scripts to map to this new layout.

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Commit messages:
 - Simplified maven copy to build dir

Changes: https://git.openjdk.org/babylon/pull/259/files
  Webrev: https://webrevs.openjdk.org/?repo=babylon&pr=259&range=00
  Stats: 1610 lines in 16 files changed: 980 ins; 325 del; 305 mod
  Patch: https://git.openjdk.org/babylon/pull/259.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/259/head:pull/259

PR: https://git.openjdk.org/babylon/pull/259