Better handle env vars DATAPATH, CYCLEFOLD_DATAPATH if already set correctly or when overriding #4
Description
Don't warn when env vars DATAPATH, CYCLEFOLD_DATAPATH already set correctly
Currently we warn in __init__() if these env vars are already set. Don't warn if they are already set to what we would want to set them anyway.
This avoids unnecessary warnings, for example when running the tests after the package has already been loaded with using.
Accidentally overriding DATAPATH, CYCLEFOLD_DATAPATH should be harder
If DATAPATH or CYCLEFOLD_DATAPATH are already set, e.g. because another RNAstructure version has been installed on the system independently of julia, and these env vars are set in .bashrc, then this package will nearly silently (it will issue an @info, nothing more) use the wrong parameters.
Solution: use RNASTRUCTURE_JLL_DATAPATH, RNASTRUCTURE_JLL_CYCLEFOLD_DATAPATH env vars to override these vars in this package.