Adding a requirements.txt file to support use outside of conda environment.  Users should build a venv, activate it, and then use `pip install -r requirements.txt` to install dependencies in the venv.

This commit establishes the temoa package within the temoa folder for purposes of segregating the temoa model code from the testing code and establishing a top-level package beneath the project top level.  All project source code is moved to the temoa package.  Also added output_files folder to catch output and tests folder for testing

No code changes, just reformatting files in the main temoa_model pkg.  Including:  Transitioning to spaces instead of tabs, using 4 spaces (mixed before), cleaned up arbritrary spacing around arguments and parens, etc.  Tried to preserve some readability formatting esp. in temoa_config.py to line up columnar things.  Re-tweaks for readability for later.

Cleaned up many unresolved references in the temoa_model pkg and the data_processing pkg.  Still work to do on cleaning up imports.  Also removed the project entry point in the temoa_model.py file and the __main__.py file and added an entry point at project top level.

Cleaned up some of the file I/O references to enable basic runs on config_sample with perfect foresight only.  The config_sample file is modified to point output to a user-supplied copy of Utopia in the output files to prevent repeated mods to the data sources.

simple run can be executed from top-level project folder with:
python main.py --config=temoa/temoa_model/config_sample

The tests folder contains files with the prefix "test_" which contain unit tests.  The remaining folders include config files utilized by the tests and sequestered database files to be used by the tests.