Test file actions for a range of file/folder combinations

[phil-davis]

• make test scenarios check that a "standard" range of combinations of file names and folder names work. For example:

• "ordinary" names like textfile1.txt (we do this already)

• names with spaces text file 1.txt and test file1 .txt

• names with ASCII special characters like !@#$%^&*()-_[]{}:;,.?=+ etc.

• names with accent, grave, umlaut - typical European character modifiers

• names with "regular" Unicode characters e.g. Nepali/Hindi script

• names with Arabic characters (a right-to-left script)

• names with emojis embedded

• sort out some test infrastructure so that we can "auto-insert" example tables of file/folder names into scenario outlines (rather than having the same list of examples pasted 100's of times through the feature files)

• sort out a way to be able to tag scenarios in the examples, so that we can choose to run only some of them on every PR, but can run all of them when we choose (e.g. in nightly test runs)

• also have combinations of folders and files that test in multiple levels of sub-folders (and that "stress" the total length of a folder/folder/folder.../filename path)

This comes out of discussion in issue #297

[phil-davis]

This will need future scheduling, and some investigation of Behat/Gherkin support.

[phil-davis]

This might also be helped by Behat/Gherkin#161 - that will allow us to have example tables with different tags for groups of examples.