Full UTF-8 Unicode Block Range Support and Unit Test Structure

[ppaulweber]

The PR sealangdotorg/libuse#25 provides a basic UTF-8 support for the libstdhl to check and convert byte sequences (strings) into a UTF-8 Unicode representation format U+{hexvalue}. Furthermore it defines a couple Unicode block ranges, but this list is far from complete.

Tasks to do:

• provide full list and ranges of all Unicode blocks through proper enumeration values (see src/cpp/Unicode{.h,.cpp}
• update the unit tests as well and fix the test case structure as proposed in UTF8 and Unicode libuse#25 (review)