Resolve "fix(build): project version variable is ignored in XML"

Description

We fixed and enhanced the way to specify version numbers that can be used in XML configuration:

• the PROJECT_VERSION variable is now correctly filled and matches the global project version number specified in the CMake project() macro.
• a new variable <target>_VERSION is now defined for each application, that matches the version used in the packaging, deduced from git tags. If a matching git tag does not exist, it fallback to the latest global tag.

Closes #1055 (closed)

How to test it?

• Launch SightViewer, SightCalibrator and dicomXplorer. Observe their application frame title name matches the latest git tag.
• Launch ExActivities, observe its application frame title name matches the current sight version number.