Require escape characters in value box inputs.

Tested in version 5.8.6

In various value boxes, it’s possible to enter non displayable characters in the value box, sometimes leading to erroneous results. For example, in a test object, using the attributes selection method, an object property was entered as

        text              equals           Download

Accidentally, a tab character was placed in the middle of the Download value (likely as an inexpert attempt at dialogue navigation), and so the value no longer matches. This was hard to detect or capture.

Potential solutions

a) Require all input to use an escaped syntax, like the regular expression syntax.

b) When the value box is collapsed (from the expanded view) replace non displayable characters by a special character like the box character.

Reason

This would improve the user friendliness of the application and reduce accidental problems and errors.