update project template

See merge request !16

The new get_imported_target_cxx_standard() function can also be used
by e.g. the EPICS IOC adapter to set the correct C++ standard flag in its
external Makefile build of the device support adapter.

update project template

See merge request !15

This allows us to use target_compile_features to set the C++ standard
in cppext and move to a newer standard.

fix(project-template): find pattern in coding style check

See merge request !14

update project template

See merge request !13

chore(project-template): remove ADAPTER=EPICS7IOC option

See merge request !12

The version of EPICS (3 or 7) is now defined by which EPICS version is
used by the found adapter. There are no distinct names any more, also
EPCIS3 is effectively phasing out.

update project template

See merge request !11

chore(project-template): remove slicing object linter warning

See merge request !10

This warning is frequently hit when using e.g. the ReadAnyGroup in
ApplicationCore, but we fail to see any benefit coming from this warning
for other scenarious. Hence we decided to disable it. Object slicing
is valid C++ and the behaviour is rather obvious.

Variable names and folders have changed in server 01.09 to adapt to
the changes in ApplicationCore 03.04, which forbids dots in variable names.
The use was inconsistent in the previous version, where dots were used for
hierarchy separators and to concatenate parts of variable names.

This commit provides a backward compatibility mapping with a switch to go to
the new naming scheme station by station for a smooth transition.

update project template

See merge request !9