Feature #2252 WaveletStat wrapper

Change Summary

Added WaveletStat wrapper and met_tool_wrapper use case
Removed deprecated OUTPUT_PREFIX environment variable
Fix pre_run_setup and post_run_cleanup functions to return True or False instead of calling sys.exit which causes a script that calls those functions to exit
Handle if INIT_INCREMENT or VALID_INCREMENT is set to an empty string for #2420
Enhanced MET config support logic so that dictionaries that contain a list of dictionaries can easily be set up to supply multiple values of the dictionary list. Previously GenEnsProd's nmep_smooth.type.method and nmep_smooth.type.width could only be configured to set a single method/width value with GEN_ENS_PROD_NMEP_SMOOTH_TYPE_METHOD and GEN_ENS_PROD_NMEP_SMOOTH_TYPE_WIDTH. These variables are still supported but users can supply additional values with GEN_ENS_PROD_NMEP_SMOOTH_TYPE1_METHOD and GEN_ENS_PROD_NMEP_SMOOTH_TYPE2_WIDTH, etc. This was done to support WaveletStat multiple values for title.location.x_ll and title.location.y_ll.

[X] Describe testing already performed for these changes:
Ran use case and confirmed it ran successfully
Ran use case with all optional configs that set MET variables and confirmed the set the environment variable values correctly
Added unit tests for new wrapper
[X] Recommend testing for the reviewer(s) to perform, including the location of input datasets, and any additional instructions:
Review changes for any typos
Review use case documentation and new Python Wrappers sections
[X] Do these changes include sufficient documentation updates, ensuring that no errors or warnings exist in the build of the documentation? [Yes]
[X] Do these changes include sufficient testing updates? [Yes]
[X] Will this PR result in changes to the test suite? [Yes]

After this PR is merged, new use case should be moved to another met_tool_wrapper group and truth data should be updated

See the METplus Workflow for details.

[X] Add any new Python packages to the METplus Components Python Requirements table.
[X] Review the source issue metadata (required labels, projects, and milestone).
[X] Complete the PR definition above.
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[X] Define the PR metadata, as permissions allow. Select: Reviewer(s) Select: Organization level software support Project or Repository level development cycle Project Select: Milestone as the version that will include these changes
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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
metplus/util/met_config.py	44	48	91.67%
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Files with Coverage Reduction	New Missed Lines	%
metplus/util/met_config.py	1	94.63%
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