[benchmarking] Make catapult converter a host side tool

As part of the plan outlined in PT-135, catapult converter will run
after the host side metrics / Fuchsia benchmark results computation.
Create a catapult converter host side tool in order to allow for this.

Also, because src/lib/uuid has a dependency on Fuchsia, inline the UUID
creation logic into catapult converter (since it's actually pretty
simple).

Add additional casts to appease the mac toolchain.

PT-135 #comment-patch

Test:
$ out/default/host_x64/host_catapult_converter_test
catapult_converter test passes on CQ
host_catapult_converter test runs and passes on CQ

Change-Id: I72e2fb62939b99701494f6f1cd7832b2882ec4f2