Fix #132 - CIF syntax errors from PyCifRW - upgrade to PyCifRW 4.2.1

[nmounet]

Fix issue #132:

• Upgrade from PyCifRW 3.6.2.1 to PyCifRW 4.2.1 (setup_requirements updated)
• All uses of PyCifRW (CifFile) modified accordingly
• Two news tests created for CifData (failing with the previous use of PyCifRW 3.6.2.1), for the square bracket syntax error and the long line error
• One test on StructureData modified (avoid asserting all the CIF comments)
• Two tests (StructureData and TrajectoryData) modified to handle better the possible absence of the PyCifRW module
• New class HiddenPrints created in aiida.common.utils, to avoid wild printouts from external modules such as PyCifRW. Used in CifData, TrajectoryData and dataclasses tests.

[ltalirz]

Thanks for looking into this! I like the HiddenPrints class, will be useful also in other contexts.
Happy to approve once the tests pass.

[ltalirz]

has the syntax really changed from keys to values?
I.e. is the result of this loop unchanged?

[nmounet]

yes (to both). Before, node.values[dataname].loops was a list, now it's a dictionary, whose values correspond to the keys of the previous version (more or less...).

[ltalirz]

Feels a bit loopy...
anyhow, thanks, just wanted to make sure.