Resolves a resource path from the classpath root

All 3 scenarios hold

A table can live in a classpath resource file instead of the annotation: @TableTest(resource = "external.table", encoding = "UTF-8").

The first three rules below call the loading API with those same arguments. Their tables can therefore show which paths resolve, what text the file's bytes become, and how loading fails.

The rules after them are driven by the very files shown. Each row comes from a line of the file rather than from the annotation.

The rule reads each file as UTF-8, and the column holds the lines of the file itself. A leading slash makes no difference, and the first row holds both spellings of a root path.