This test case ensures that the CPack External generator produces
the proper .json file, and also ensures that the version negotation
with CPACK_EXT_REQUESTED_VERSIONS works properly.
Adds support for epoch version to CPackRPM and
CPackDeb packagers.
Also adds better version checking to CPackDeb
that complies with Debian rules.
Fixes: #17057
Content list for a certain test
should be the same between different
generators so whenever possible use
a single expected files list per
file for all generators.
Each generator generates its own file
format with different extensions but
they all create those file names by
a certain pattern and all of them
require the same pieces for that pattern
to work. Now we can only provide pieces
once and and each generator will use those
pieces to generate an expected file name.
Format a `message(FATAL_ERROR)` call with markup to make the generated
message more readable so that the difference between the actual and
expected results is easier to see.
Package file names that are found during validation
should be preserved in FOUND_FILE_${NO} variables
that can be later used in custom VerifyResult scripts.
