appveyor: run VS2008 job with old CMake 3.12.2

appveyor: run VS2008 job with old CMake 3.12.2

Switch VS2008 job the oldest runner machine. It adds the oldest CMake to
the Windows mix, from 2018-11-30. Not a beauty, missing support for `-B`
and Unity, but it's a version curl supports. It's newer than Old Linux.
The previous oldest was 3.16.2. It remains used with VS2010-VS2017.

Also:
- fix VS2008 job to actually build examples.
- switch VS2019 job to OpenSSL 1.1.0 that wasn't tested before.
  Migrate OpenSSL 1.0.2 to the VS2008 job.
- measure run time of individual build steps.

Follow-up to 01c25e3b008085a7944f3eea4971f5eb469a6c49 #16458
Closes #16505