Enhancement: Allow `TC_STAT_LOOKIN_DIR` setting to accept multiple entries, update documentation

[j-opatz]

Describe the Enhancement

In a recent Discussions topic, the TC_STAT_LOOKIN_DIR setting was discussed. Two issues were discussed, and this issue is to correct and enhance the setting:

1. First, the METplus wrappers documentation says the TC_STAT_LOOKIN_DIR is only for the directory that TC-Stat will look in for files. However, this setting is a wrapped extension of the -lookin flag for MET's TC-Stat tool, which can accept a file or a top-level directory that contains the files. This should be tested to ensure the behavior is as expected, and then update the METplus wrappers documentation to show the dual behavior capability.
2. The -lookin flag can accept multiple entries. This is a desired behavior in the METplus wrapped tool version. We should confirm that this behavior is currently unavailable, and then enhance the wrapped tool to add this behavior.

Time Estimate

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Issues should represent approximately 1 to 3 days of work.

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Define Related Issue(s)

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• METplus, MET, METdataio, METviewer, METexpress, METcalcpy, METplotpy

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