Added code for running with WRF-Chem instead of TM5

This is the initial commit for running CTDAS with WRF-Chem instead of TM5. The commit contains new files for observationoperator, statevector, rc files and WRF-specific tools. In addition, it contains new files with WRF-specific versions of pipeline and column observations. They are based on python 2 versions from mid 2019. In a future commit, the code will be updated to work with the current versions of these files in the master branch. However, in the case of column observations, this includes changes to the input file format. To facilitate migration from the original python 2 code to python 3, the old file (and thus format) is kept in this commit.