Prepare cpptango 9.4

[bourtemb]

Conda recipe to build a cpptango 9.4 package based on tango-9-lts cppTango development branch.

[bourtemb]

The commits history is not clean but squash commits could be used when merging.
@ajoubertza , maybe you can work with the generated packages from this PR if you want to test cpptango tango-9-lts with pytango while I'll be on vacations.
I think there is still some work to be done in order to eventually generate several cpptango and tango-test packages in the github workflow for cpptango 9.3..x and cpptango tango-9-lts branch.
We have to discuss about how do we deal with these different versions (several branches, several directories with several recipes for cpptango, ...).

[bourtemb]

You can get the packages from the github workflow artifacts: https://github.com/tango-controls/tango-conda-recipes/actions/runs/164651901

[ajoubertza]

@bourtemb I've tried out the new 9.4.0alpha cppTango and TangoTest Conda packages with PyTango. After changing PyTango to use libtango.so.94 instead of libtango.so.9, the extension built successfully. All the tests passed as well. 👍

(env-py3.7-tango9.4.0) root@0ec801bc9fc5:/opt# python
...
>>> import tango
>>> print(tango.utils.info())
PyTango 9.3.3 (9, 3, 3, 'dev', 0)
PyTango compiled with:
    Python : 3.7.7
    Numpy  : 1.18.5
    Tango  : 9.4.0
    Boost  : 1.67.0

PyTango runtime is:
    Python : 3.7.7
    Numpy  : 1.18.5
    Tango  : 9.4.0

PyTango running on:
uname_result(system='Linux', node='0ec801bc9fc5', release='4.9.125-linuxkit', version='#1 SMP Fri Sep 7 08:20:28 UTC 2018', machine='x86_64', processor='')

(env-py3.7-tango9.4.0) root@0ec801bc9fc5:/opt/pytango# python setup.py test
...
========== 755 passed, 21 xfailed in 84.72s (0:01:24) ==================================