Add CMake support for native compilation.

[powderluv]

Add a single CMakeLists.txt to support building natively on
systems like aarch64 where bazel support is lacking. Also keep
all CMake files in one file to not confuse the supported
bazel way of building.

TEST=run examples on Gentoo 64 bit RPi4 with Coral and x86
TODO: Add the skipped examples / tests

powderluv@pi64 ~/github/edgetpu/src/cpp/b $ LD_LIBRARY_PATH="."
./classify_image -image_path parrot.bmp -labels_path
inat_bird_labels.txt -model_path
mobilenet_v2_1.0_224_quant_edgetpu.tflite

Zonotrichia querula (Harris's Sparrow)
Score: 0.996094

Score: 0

Score: 0

[googlebot]

We found a Contributor License Agreement for you (the sender of this pull request), but were unable to find agreements for all the commit author(s) or Co-authors. If you authored these, maybe you used a different email address in the git commits than was used to sign the CLA (login here to double check)? If these were authored by someone else, then they will need to sign a CLA as well, and confirm that they're okay with these being contributed to Google.
In order to pass this check, please resolve this problem and then comment @googlebot I fixed it.. If the bot doesn't comment, it means it doesn't think anything has changed.

ℹ️ Googlers: Go here for more info.

[powderluv]

updated for diploria3 in this PR #59