Update inspect_folia script to run all tests

Previously, the inspect_folia script stopped immediately after it found
an error in a folia document. Because it makes more sense to see a
complete report about a folia document, the script was updated to run
all tests for a document.
Fix check for known unexpected elements

There is a distinction between known unexpected elements and unknown
unexpected elements. Previously, documents were considered to be valid
if they contained known unexpected elements. However, this is not
right, because it is not clear how to translate these known unexpected
elements to kaf. Therefore, the script now judges a folia document
invalid if a known unexpected element is found.
Add events without class to known unexpected elements of acts
Move assignment of all elements to be inspected to the top

There are plays without scenes. The inspect_folia script was expecting
that all plays have scenes. An act in a play without scenes is expected
to have different elements than an act in a play with scenes.
Assignment of elements to be inspected was moved to the top of the
script, so that expected elements can be made dependent on the
occurrence of other elements.
Add expected elements to acts for plays without scenes

If a play has no scenes, acts are expected to contain speaker turns and
stage directions. The inspect_folia script was updated to reflect this
assumption.
Fix newlines in reports for invalid folia files

No newlines were printed in the reports for invalid folia files. This
was fixed by putting the output of the inspect_folia script to a
temporary file and then copying the contents of the file to the error
report. The error reports are now more readable.