cleanup workflow script

use new fixed directory names to simplify handling of versions etc.
openssl/(CK_OPENSSL_VERSION) -> openssl/current
zlib/(ZLIB_VERSION) -> zlib/current
libssh/(LIBSSH_VERSION) -> libssh/current
kerberos/kfw -> kerberos/current

Now version variables are used for definition of download URL and for description not for building path etc.

reorder arguments for "run" steps to be more readable
1. is environment variables setup
2. working-directory
3. script
4. use shell argument as end tag (it is always indented)

fix some download issues and change some url's to be more consistent
by example all versions of openssl is downloaded from github openssl release store, not mixed with other sites
fix problem with download from sourceforge site for Regina interpreter

use working-directory run argument whenever possible
use absolute path for configuration scripts (by example setenv.bat) which doesn't depend on working directory