Get acquire-common building

[aliddell]

Includes all commits from acquire-core-libs, acquire-video-runtime, and acquire-driver-common.

• Removed the PR template. It was a mistake.
• Added @file docstring directive and brief description to all tests.
• Moved write-side-by-side-tiff.cpp to tests under acquire-driver-common (previously under acquire-video-runtime).
• Did a little additional validation in change-external-metadata.cpp.
• The base CMakeLists.txt files for each of the subprojects were all simplified, since there's a new base project where all that can be handled.
• CPack builds one big distributable, but it includes all the static libraries, headers, and the acquire-driver-common DLL.
  • Note that git versioning no longer works the way it used to, because we don't have separate git histories or tags for subdirectories, i.e., acquire-core-libs, acquire-video-runtime, and acquire-driver-common will all have the same versions from now on. I propose we go to 0.2.0 to reflect this change.

[andy-sweet]

Generally looks great. Approving because CI is passing and I was able to build, test, and install successfully.

Most of my comments are small suggestions or questions.