Part of #5775.
* Create _internal folder certbot-nginx
* Move configurator.py to _internal
* Move constants.py to _internal
* Move display_ops.py to _internal
* Move http_01.py to _internal
* Move nginxparser.py to _internal
* Move obj.py to _internal
* Move parser_obj.py to _internal
* Move parser.py to _internal
* Update location and references for tls_configs
* exclude parser_obj from coverage
Part of #5775. Methodology similar to #7528. Also refactors NGINX test util to use certbot.tests.util.ConfigTestCase.
* refactor nginx tests to no longer rely on certbot.configuration internals
* Move configuration.py to _internal
* Remove unsupported pylint disable options
* star-args removed in Pylint 1.4.3
* abstract-class-little-used removed in Pylint 1.4.3
* Fixes new lint errors
* Copy dummy-variable-rgx expression to new ignored-argument-names expression to ignore unused funtion arguments
* Notable changes
* Refactor to satisfy Pylint no-else-return warning
* Fix Pylint inconsistent-return-statements warning
* Refactor to satisfy consider-iterating-dictionary
* Remove methods with only super call to satisfy useless-super-delegation
* Refactor too-many-nested-statements where possible
* Suppress type checked errors where member is dynamically added (notably derived from josepy.JSONObjectWithFields)
* Remove None default of func parameter for ExitHandler and ErrorHandler
Resolves#5973
* Highlight failures more with asterisks
* Filter out wildcard names from all_names
* Only test -ai, not -aie (no redirects)
* Modified versions of almost all of 79 configs corpus
* Re-enable now-working stanza with 301 redirect
* Change another redirect to go to :443
