[test] use TemporaryDirectory context manager For consistency with others tests, use TemporaryDirectory from cubicweb.devtools.testlib.

[tox] Drop "exclude" option from flake8 config and adjust flake8-ok-files.txt accordingly Some files listed in flake8-ok-files.txt were excluded of flake8 run because of the "exclude" option in tox.ini. Some of them were non-existent files (moved), some others were actually non-flake8-compliant. In the latter case, we adjust trivial errors (blank lines, module import not on top of file) but remove others (like cubicweb/test/unittest_utils.py) from flake8-ok-files.txt.

[autoform] Go through guess_field even when field class is specified using uicfg guess_field does not only find the proper field class for some attribute/relation, but also do some basic configuration depending on e.g. constraints. Before this patch, if one was specifying explicitly the field class using uicfg.autoform_field, this automatic configuration wasn't happening. Change form.field_by_name and ff.guess_field so explicit class are also automatically configured now. Closes #14474840

[uilib] Fix incorrect serialization of python dicts into javascript objects Valid javascript object keys must be surrounded by quotes unless they are valid javascript identifiers. Valid identifiers are a defined by complex and changing specs, so it is much simpler to always use quotes. Closes #17046704.