Option to change between rich <html-description> and plain <description>

As user i want to have the possibility to change the description format for the TestBench project dump.

Libdoc2TestBench shall use the argument `-s` / `--specdocformat` for this option.
If set to `RAW`, `<description>` shall be filled.
If set to `HTML`, `<html-description>` shall be filled.
